CH660927A5 - MONITORING SYSTEM. - Google Patents

Description

The invention relates to a monitoring system according to the preamble of claim 1.

Such a monitoring system is described in DE-OS 2 638 529.

In such monitoring systems, the sensitivity of the sensors connected to the signaling units can change over time due to aging; voltages for operating these sensors or reference voltages can also drift over time.

The present invention is therefore intended to create a monitoring system according to the preamble of claim 1, in which long-term changes in system parameters are compensated automatically.

This object is achieved according to the invention by a monitoring system according to claim 1 or alternatively by a monitoring system according to claim 2.

In the monitoring system according to the invention, these long-term changes are compensated for without the operation of the monitoring system having to be interrupted. The individual sensors can be calibrated remotely from the central unit in real time without affecting the operation of the system. According to the invention, compensation signals can be generated for very different types of sensors, taking into account the influence of various variables, e.g. changing the wind speed, temperature, humidity, supply voltage for a sensor connected to a signaling unit, etc.

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The invention is explained in more detail below with reference to the drawing. In this show:

Figure 1 is a block diagram of a known monitoring system;

Figure 2 is a block diagram of a monitoring system with various reporting units;

Figure 3 is a circuit diagram of part of the central unit of the monitoring system and a reporting unit;

Figures 4 and 5 graphical representations of the time course of signals on the signal rail of the monitoring system;

FIGS. 6A to 6C excerpts from the representations of FIGS. 4 and 5 on an enlarged scale;

FIG. 7 shows a block diagram of a signaling unit of the monitoring system;

FIG. 8 shows a more detailed circuit diagram of a signaling unit;

FIG. 9 shows the block diagram of an integrated circuit of the signaling unit shown in FIG. 8;

FIGS. 10 to 12 are graphical representations which are used to explain the information transmission between the reporting units and the central unit;

FIG. 13 shows a block diagram of an evaluation circuit of the central unit;

FIG. 14 shows a block diagram of a modified central unit with several monitoring channels;

FIG. 15 shows the block diagram of a part of the central processing unit which compensates for long-term changes in system parameters;

FIG. 16 shows a schematic representation of a part of the central unit, the signal rail and signaling units connected to it, on the basis of which the search for interruptions in the signal conductors is explained;

FIG. 17 shows a block diagram of a large monitoring system with a plurality of central units monitored by a main central unit; and

FIGS. 18 to 20 graphical representations of the time course of signals on the signal rail of the monitoring system, on the basis of which the transmission of data and commands from the central unit to the signaling units and vice versa is explained.

FIG. 1 shows a known monitoring system with a plurality of signaling units 20 connected between two lines 21, 22. A control panel 23 is connected to lines 21 and 22. At the other end, the lines 21, 22 are terminated by a terminating resistor 24. With this arrangement, the actual message is sent by one of the signaling devices, which senses fire or the presence of certain substances, is thereby placed in an alarm state and causes a change in the voltage or the current in the line pair, which is picked up at the control panel. With this arrangement, it is only possible to determine the loop on lines 21 and 22 on which the alarm condition occurred, but not the exact location of the alarm.

Fig. 2 shows an arrangement of the previous system with several answering devices 25 instead of the simple signaling devices, which work together with a regulator or control device which is connected to the same pair of lines 27, 28 to which the transponders are connected. The term “transponder” used means a device that can monitor or control a state or an assigned component, is optionally addressed by the control unit and not only recognizes its address but also other data that are transmitted from the control unit, such as commands for the Self-control of the transponder or the control of various assigned devices. In addition, the transponder itself transmits data such as the converter response signal and the identification response signal back to the control unit. The answering devices 25 thus interact with the control device and form a two-way two-way traffic system. The individual transponders are not passive devices that only transmit a signal when they are acted upon by a main signal transmitter. It should also be emphasized that the line pair 27, 28 or one of the other pairs 31, 32 and 33, 34, which branch off from the main pair 27, 28 in area 2, have no termination devices. It will be apparent that this branch is possible regardless of the physical arrangement or the order in which the individual responders are addressed. This system without the need for a termination at the end of the individual pairs of conductors results in a device whose installation and operation are simple and economical.

3 shows in a simplified form the implementation of oncoming traffic signaling between the central unit 26 and a transponder 25. The control unit 26 operates with a reference voltage V which is present between the lines 35, 36. The line 35 is connected via a resistor R1 to a line 37 which is connected to the line 27 via a connecting screw 38. The line 36 is connected to a line 28 via a screw 40. A switch S1 is connected in parallel to the resistor R1. Another resistor R2 is connected between lines 37 and 36. One side of a measuring line 41 is connected between the resistor R2 and the line 37 in order to obtain an indication of the voltage present at the resistor R2.

One side of a resistor R3 is connected to line 27 and its other side is connected to line 28 via a further switch S2. In the preferred embodiment, all resistors R1, R2 and R3 have the same value. However, it can be seen that other values or ratios can be selected without departing from the principles of the invention. A command circuit 42 regulates the opening and closing of the switch 1, and further components of the transponder 25, not shown, regulate opening and closing times of S2. 3 are explained in more detail below.

'' The exchange traffic explained in the previous application is carried out with the modification via at least one characteristic, e.g. the voltage amplitude or the duration of a signal or by changing more than one characteristic, e.g. of time plus amplitude. The amplitude of the signal voltage is easily controlled by switches S1 and S2. The switch S1 is closed in order to send each signal or each pulse of each signal group of the pulses of the control device via the line pair 27, 28. The closing time of the switch can also be read on the transponder, as can the number of opening and closing cycles of switch S1 in the individual signal or pulse groups.

If RI, R2 and R3 have the same resistance value and the switches S1 and S2 are open, then the voltage on the measuring line 41 is V / 2 and is determined by the resistance bridge with the resistors R1 and R2. If the transponder 25 in the control unit thus responds, a voltage V / 2 present on the measuring line 41 means that the switch S1 is open. If S2 is closed while S1 remains open, R3 is in parallel with R2, this parallel connection being in series with R1 to determine the voltage on line 41. Thus, when switch S2 is closed, measuring line 41 measures a voltage level of V / 3 that goes to the control unit

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runs back. This can also easily determine the number of opening and closing cycles of the switch.

The closing time of S2, as long as S1 remains open, can be designed as a function of a signal that comes from an associated converter (not shown) or as a function of a desired data-carrying signal. By measuring the duration of the closing time of S2, the data represented by the original signal can be determined. The closing time of S1 can be regulated in such a way that the generation of commands from the control unit to the transponders is controlled.

The control unit 26 obtains data from the responding transponder by measuring the closing time of S2 or the time during which the voltage V / 3 is applied to R2. It is advantageous that important data can often be tapped by the control unit if one or more additional transponders respond simultaneously with the addressed transponder. For this purpose, the control device 26 must be able to distinguish when and by how much the voltage on the measuring line 41 drops below V / 3. For this decision, the control unit 26 contains a signal test circuit 43. The test circuit 43 contains a voltage divider 46 with four resistors 45, 46, 47 and 48, which are connected in series between a unidirectional voltage source and ground. An arrangement 50 comprising comparison elements 51, 52 and 53 is connected in such a way that in each case one input is connected to the measuring line 41 and the other input is connected to a connection of the voltage divider 47. The comparator 51 outputs an output signal to a line 54 when the signal on the measurement line 41 is V / 3 or less (plus or minus a corresponding tolerance). This means that at least one transponder responds by closing its switch S2. It is essential to the invention that the comparator 52 outputs an output signal to a line 55 if the signal on the measurement line 41 is V / 4 or less (again plus or minus a corresponding tolerance value). Such an output signal indicates that two or more transponders respond, each closing a switch S2 and switching its corresponding resistor R3 in parallel with R2. By logically comparing the output signals on lines 54 and 55 at any moment, the presence of a signal on line 54 and no signal on line 55 indicates that one and only one transponder is reporting back via lines 27, 28. Equally important is the wiring of the comparator 53, which emits an output signal via a line 56 to a command circuit 42 when the amplitude of the signal on the measuring line 41 is at a level of V / 5 or less. This means that three or more transponders respond or that there is a short circuit between lines 27, 28. Under these conditions, the output signal on line 56 is used to switch off the command transmitter circuit 42 and to indicate the fault condition. By a logical comparison between a signal on line 55 from comparator 52 and a determination that command circuit 42 is not switched off, it can be determined that two transponders are responding (signal on line 55) and that a third transponder is now not reporting back , because otherwise this would have been indicated by a signal which would have been fed back via line 56 to switch off the command circuit 42.

If n is the number of comparison elements in the test circuit 43 of FIG. 3 (in the exemplary embodiment shown, n = 3), then n-1 of the responding transponders can be specifically identified. If, on the other hand, answers n or more transponders or if there is a short circuit between lines 27 and 28, this is considered an unacceptable working condition and this is indicated by an output signal from comparator 53 on line 56.

A description of the signal groups that are transmitted by the control unit and returned by the transponder should serve to better understand the functioning of the system. FIG. 4 shows a series of signal groups for serial transmission via lines 27, 28 to various response devices connected to these lines. Each individual signal group, like the group shown under the heading “Transponder 1”, contains the same number of pulses. In a preferred embodiment, four pulses were used for a transponder address in each group, but it can be seen that a different number of pulses can also be used. The extended high-level pulse under «Address 31» and the first part of «Address 0» indicates a deletion process and also serves to charge a component in the transponder so that it remains active during the call cycle. Each transponder contains a counting circuit for summing the number of pulse groups that are transmitted over the lines, which is acknowledged when its address is displayed on the control unit. All other high level pulses (after address 0) of FIG. 4 are of short duration and mean that the control unit has not issued a command, but only different addresses which are indicated by the number of pulse groups. Figure 5 shows the manner in which a pulse group is modified to route a command to a particular transponder. When the seventeenth transponder is called, the high level portion of the second pulse of the group is extended for a significant amount of time, which may be 40 milliseconds. The exact period of time is not critical because the individual transponders can contain a simple clock which determines when the pulse amplitude has been high for a minimum time, which is shown in FIG. 5 the distance between to and ti. This time span was approximately twenty milliseconds in the preferred exemplary embodiment and represents a “waiting time”. Since the transponder recognizes that this is the second incoming pulse, it also “knows” the function to be carried out if the high-level part of the pulse exceeds the “ Waiting time »ti is extended. Assume that the extension of the second pulse denotes a command to switch on a light-emitting diode or another corresponding optical display. As soon as the high-level part of the pulse extends beyond ti, the light emitting diode is switched on and remains on until time h. The transponder can accept different commands because different high-level pulses in the group are extended or "stretched" to different widths. This means that the control unit can change the closing time of S1 and thus the duration of the high-level pulses (such as the pulse between to and t2), which encodes data in addition to that shown in the exemplary embodiment, which results in a considerable versatility of the system results. It should be noted that after the waiting time, the corresponding component (light-emitting diode, relay or another unit) is acted on as long as the pulse is still high. This means that the voltage of this component is supplied by the control unit via lines 27, 28 and not by the transponder. This is explained in more detail below. In the same way, the transponder returns data by closing its switch S2 and generates a data return signal with the amplitude V / 3 analogous to the extended closing of the switch S2 in FIG. 3. This becomes closer with reference to FIGS. 6A, 6B and 6C explained.

6A, 6B and 6C serve to explain the data transmission from one of the transponders 25 to the control 4

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device 26. This is carried out with the switch S1 of the control device in the open position, the switch S2 of the transponder optionally being closed for data transmission. Each time the switch S2 is closed, the voltage of the measuring line 41 of the control device assumes the level V / 3. The length of the time span in which the voltage on the measuring line 41 remains at V / 3 depends on the control unit (duration of the interrupted SI) and also on the transponder (duration of the closed S2). The closing time of S2 in turn depends on a characteristic of a signaling device or another transducer connected to the transponder (such as the amplitude of the voltage) or also on the data generated in the transponder. The assigned detector (or converter) or the internal data generation is explained in more detail below.

FIG. 6A shows one of the pulse groups in FIG. 4 under the headings “Transponder 1” and “Transponder 2”, the scale being enlarged compared to that of FIG. 4. In FIG. 6A, four pulses are low-level, the low amplitude part of the individual pulses being identified by 141, 142, 143 and 144. The fourth low-level pulse part 144 occurs in the time period 145, this time period being again divided into three time intervals or “blanking windows” 146, 147 and 148 in this exemplary embodiment. It is obvious that any number of blanking windows or time periods can be generated depending on the level of accuracy required. With the fourth low-level period of time there is a transition or a zero crossing 150, which takes place in the center of the key window 145. This transition or zero crossing lies in the «normal key window» or key window 147 and indicates the normal operation of the component in question (regardless of whether it is an assigned converter or an internal component of the transponder), which contains the data for the return in interval 145 generated. For example, this could report the normal state of a closed signaling device or the interruption of an assigned switch. If the zero crossing in the initial part of the interval 145, i.e. would occur in the blanking window 146, this is an indication of a low-level voltage and can be used to indicate a fault in a connected signaling device or that a switch is not connected. If the transition in the tactile window 148 takes place towards the end of the interval 145, this can be a signal, for example, that the assigned signaling device is in the alarm state or a connected switch is closed. It should be noted that the duration of the initial part of the low-level pulses before the transition represents the amplitude of the voltage on the transponder. Of course, this time period could also be selected depending on other parameters such as frequency or current level. In addition, converters other than smoke detectors or switches can generate status-indicating feedback signals in the scanning interval 145. For example, if a temperature indicating transducer were connected to the transponder, a zero crossing in the key window 146 could indicate a low temperature, a zero crossing in the key window 147 a medium or normal temperature, and a zero crossing in the key window 148 could indicate a high temperature. Although transition 150 has been discussed in more detail in the general description of FIG. 6A, it should be noted that the timing diagram of the invention is not dependent on the transition and zero crossing as such. The system, on the other hand, continuously checks the level of the voltage during the interval 145 at specific points in time and adds a count that relates to the period in which the signal stays at the level V / 3 during the time interval 145. This means a significant improvement in noise sensitivity and measurement accuracy, as will be explained in more detail below. Those skilled in the art will recognize that many changes can be made to this versatile system in the simple system and feedback displays of FIG. 6.

The interval 145 was extended or "stretched" by the S1 which remained open in order to create a corresponding period of time since the amplitude characterizes a corresponding analog voltage level. Of course, any other of the low pulse levels 141, 142, or 143 could be lengthened to report data back, but the lengthening of the retransmitting data would be different. In the illustrated embodiment, an extension of the first pulse 141 allows the transponder to transmit all of its calibration data based on a reference voltage. The expansion of the second pulse depth 142 enables the transponder to generate data for identifying the converter or another component connected to the transponder. An extension of the low-level voltages 143 or 144 allows the transponder to report data back via an analog signal delivered to the converter. In the example, only a low pulse level was extended,

however, with a single feedback, multiple low level pulses can be stretched. On the other hand, no low-level pulses are extended if no data are to be reported back. This means that 0, 1, 2, 3 or 4 low pulse levels can be extended in a single pulse group, four pulses serving for one transponder address in the exemplary embodiment.

If the first two low pulse levels 141, 142 fall below line 430, but do not reach line 431, the control device can determine (by checking the voltage level on measurement line 41) that transponder switch S2 was closed. Closing the switch directs the voltage level V / 3 on the measuring line 41, this level being in the amplitude range formed by lines 430 and 431. At the point in time at which the third pulse 143 would be transmitted by the transponder, no converter being connected to the transponder, to which there is also no zero signal level, its switch S2 is interrupted. At this time, the voltage level on the measurement line determined by R1 and R2 is V / 2, which is represented by the low pulse level 143 of FIG. 6A. This response behavior at level V / 2 generates data, namely that at this point in time no S2 is connected in the addressed or another transponder.

If a smoke detector designed as an ion probe were connected to the returning transponder, the extended low pulse level could transmit data in the time interval 145 as follows. The entire time interval has a duration of 32 ms, the voltage amplitude being displayed in the range from 0 to 8 V. Thus, each millisecond of the pulse duration represents 0.25 V. In this exemplary embodiment, the first or fault key window extends over 12 ms and represents 3 V. The normal key window 147 has a duration of 8 ms and denotes 2 V; the third or alarm button window has a duration of 12 ms and shows 3 V. Thus, when transition 150 of Figure 6A occurs, the transponder reports to the controller that a voltage level of 4.0 V is present at the corresponding input of the transponder from the associated transducer, in this case a smoke detector designed as an ion probe. The controller then determines, based on this voltage level, how far this voltage (4.0 V) is from the reference level for that particular converter by the

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Determine the switching state of the converter. In addition, this actual voltage level can be compared with a previously recorded voltage level of the same converter. If the previous voltage level was registered a relatively long period of time, such as a week or more, the comparison may provide an indication of slow changes in the operation of the detector, which may result from aging of components or accumulation of dust. By recording the size of the change in the mode of operation of the signaling device, the change in the system can be compensated for and thus a false indication for alarm or other operations can be avoided. In addition, the magnitude of the change caused by dust or aging can be used to indicate that maintenance is required (cleaning or other repairs to the system) in order to avoid unwanted alarms or unwanted faults. By compensating for long-term changes in the voltages of the signaling device, the control device can continuously determine the actual sensitivity or the "alarm-remote" of the individual signaling devices. It is a significant advantage over the earlier plant and plants of the prior art.

In this embodiment, only three touch windows or measurement intervals are used to simplify the explanation. If the transition 150 had occurred in the key window 146, this would have occurred in the time range from 0 to 12 ms and would represent a voltage amplitude of 0 to 3 V on the signaling device. A transition or zero crossing in this area means that there is a fault, such as an interrupted circuit on the connected converter or a malfunction in a circuit of the converter. If the transition occurs in the third key window 148, this indicates a voltage in the range of 5 to 8 V over a period of 20 to 32 ms. A transition in this time range indicates that the connected converter is in the alarm state when this signal is processed on the control unit. That is, the controller compares the return signal to the previously stored alarm reference threshold level, and when it determines that the return signal is above this level, the controller indicates the alarm condition. It is evident from this that a clock generator arrangement is required in the control device in order to identify the exact duration of the signal returned via the measuring line 41, and this is explained in more detail with reference to FIG. 13. For now, it may suffice to note that the timing is measured in the control unit and therefore neither the transponder nor an assigned converter can trigger an alarm. In this embodiment, the controller determines and indicates when an alarm or fault condition occurs on a particular transponder.

Fig. 6A shows the frequency response when a single transponder closes its switch S2, but Fig. 6B shows the frequency response when the switch S2 of another transponder (i.e. an unaddressed transponder) has failed in the short circuit position. I.e. S2 of the other transponder remains closed for the entire time in which the data from the addressed transponder is returned. The ability to "read across this short circuit" is an important advantage of the invention. In Fig. 6A, the negative excursions of the first two pulses were between lines 430 and 431. These lines have the same reference numerals in Fig. 6B. Line 430 represents a voltage level between V / 2 and V / 3 and reference line 431 represents a voltage level between V / 3 and V / 4. Line 432 represents a voltage level between the amplitudes V / 4 and V / 5. If S2 of the one transponder is closed, then the resistor is R3

this transponder is connected in parallel to R2 of the control device and generates a voltage level of V / 3 on the measuring line 41. This results from the negative deflections of the first, second and third pulse of FIG. 6A. However, since the switch S2 of another transponder has failed in the short-circuit position, an additional R3 is connected in parallel with the other resistors, which results in a negative deflection of the first, second and fourth pulse from level V / 4 (FIG. 6B). 6B shows that the data can be received and evaluated by the addressed transponder despite the short-circuited output of the additional transponder. The returning signal can easily be checked by measuring the time period in which the pulse amplitude remains at the level V / 4 from the beginning of the interval 145 to the passage 150. The measuring method for this period is explained in more detail with reference to FIG. 11. By measuring this time interval, the control unit can “read” the short circuit and determine the data that are supplied by the responding transponder. The earlier systems do not have this possibility of reading and also writing over the short-circuited output of a transponder and are considered an important advantage of the invention. 25 connected systems usually depend on the correct operation of the previously addressed transponder so that a subsequently addressed transponder returns the correct data. In some systems, the insufficient mode of operation prevents the return of all data from 30 subsequently addressed transponders. Digital systems mostly depend on the correct operation of all transponders. If the output of any transponder is short-circuited, no usable data can be received. If two or more transponders transmit data 35 simultaneously, no distinguishable data can be received here either.

FIG. 6C shows another type of response, with an additional transponder not being short-circuited, but still reporting data back together with the addressed 40 transponders. Here, too, the first two pulses reach level V / 4 in that S2 of the two transponders close at the same time. However, one of the two S2 is closed during the third pulse interval, and therefore the control unit can determine that the second transponder is not short-circuited, but that both are delivering data simultaneously. During the extended pulse interval 145, the first part 160 of the pulse is at the V / 4 level. However, there is a first transition 161 with a subsequent part 162 at the level V / 3, a second transition 163 before the pulse returns to the level V / 2 in the final part 164. If both transitions 161, 163 fall into the normal key window 147, the control unit “knows” that there is no alarm state. If a response falls within the alarm range, the control device "knows" that a signaling device is at the alarm level, but cannot now identify the signaling device that is returning the alarm signal. The time interval 165 represents the lower analog voltage value of the two returning signals and the time period 166 the higher of the two 60 values. If the period 166 had been extended into the alarm key window 148, the control unit could determine that one of the two responding transponders reports back an alarm level signal.

Fig. 7 shows the functional arrangement by which the 65 signals output by the control device are processed by the transponders receiving them. The signals present via the lines 27, 28 arrive at a voltage crossover 60 which has a DC control voltage

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difference for the components of the transponder via a line 61 to individual ones of these components and via a line 62 to the assigned components (such as a signaling device). It can be seen that the line 61 can represent several lines, e.g. a ground line, a line of 5 V to ground, another with 12 V to ground, etc. The signals coming from the lines are forwarded from the voltage busbar 60 to a busbar 63, which in turn sends the signals to an address detection circuit 64 and a Output command controller 65 passes. Address selection switches represented by block 66 are individually connected to address detection circuit 64. The switches are simple on-off switches that can be individually switched to the open or closed position, and together they determine the address of the special transponder in which the circuit is arranged. With five switches in the illustrated embodiment, up to 32 addresses can be individually assigned by opening and closing different switches. These switches thus represent switching devices for determining the only address of the transponder in which they are arranged. A comparator or other arrangement in the detection circuit 64 recognizes the correspondence with the single address received from the lines via the busbar 63, which is set by the switches 66, the circuit 64 recognizing a drive signal on a line 67 when this coincidence is identified an analog shaping circuit 68 and the output command control

65 issues.

The analog shaping circuit 68 comprises a device which detects when a command is pending from the control unit and represents the corresponding circuit connections required by the command. The analog shaping circuit 68 also has a first analog signal via a line 70, which is zero V in this exemplary embodiment , and a second analog signal for a line 71. The analog signal can be any type of data identification signal. For example, a signaling device 62 is coupled to the analog shaping circuit 68 via the line 71. When the circuit is instructed to report data back to the controller via the analog signal on line 71, the analog shaping circuit transmits the data feedback signal, which is generated as a function of the analog signal on line 71, via bus bar 63 and voltage-current switch 60 the power lines and from there to the control unit. In this way, the sensitivity level of the special signaling device can be monitored with every work cycle, if this is desirable or necessary under certain conditions. A reference or calibration voltage reaches the analog shaping circuit 68 via a line 73. This reference voltage can be taken from a Zener diode (not shown) or another suitable device. The reference or calibration voltage is fed back to the control unit on request so that it can validate the operating state of the transponder. For the route of the description and the claims, line 73 represents the generator for the reference voltage.

A plurality of device identification switches 74 are also connected to the analog shaping circuit 68. Like the switches

66, the identification switches 74 are also simple on-off switches, but they can be a suitable device for closing a crisis for the largest negative or positive busbars. These switches can be set to generate a numerical combination (from 1 to 8 in this embodiment) to identify the type of converter (such as the annunciator 72) that

answers over the power lines. For example, the setting of these switches can be the type of transducer connected as a smoke detector of the ion probe type, photoelectric smoke detector, a device for identifying the air speed, a temperature-indicating unit, a mechanical switch as used in manually operated train detectors (toggle switch), a short-time switch for blowing off Halon or other device. The analog shaping circuit also controls the display signal to the output command control 65 that a specific command has been recognized on the busbar 63, the output command control 65 now also being controlled via the line 67. This control can perform many functions. For example, a signal can erase an electromechanical actuator, which is shown here as a current surge relay 75. A signal on line 76 can command this operation, with contacts 77 being moved from the position shown to the second position (erase position). A signal from the output command control 65 on line 78 can switch the contact group into the switch-on position shown. Another possibility is to send an output command over a line 80 to light a signal lamp 81 like a light emitting diode.

8 shows a basic circuit diagram of a transponder used according to the invention. Two screw terminals 83, 84 connect the power lines 27, 28 to the lines 85, 86 of the transponder. An overvoltage protection 87 is connected between the lines 85, 86 in order to protect the components of the transponder against transients from the network. A diode 88 is connected between the signal line 85 and the main power line 90 of the transponder. One side of a capacitor is connected to line 86 and its other plate is connected to the common node between the main power line 90 and the cathode of the diode 88. When a long pulse with a positive transition is present at the transponder, current flows through the diode 88, which charges the capacitor 91. The charge on capacitor 91 maintains the voltage on main power line 90 during normal operation when the lines are low, i.e. when the voltage on lines 27, 28 is at V / 2 level or less. The voltage on line 90 is present at the collector of an NPN transistor 92. which is connected as a series regulator in order to deliver a regulated output voltage to a line 93. A resistor 94 is placed between the collector and the base of the transistor 92, the base also being coupled to the line 86 via a zener diode 95. A resistor 96 is connected between the line 90 and, via a line 99, to the input connection 10 of an integrated circuit 1.

If the voltage level on the power lines 27, 28 changes, there is a corresponding change in the amplitude of the signals present at the pin 17 of the integrated circuit 1. A low-pass filter, consisting of a resistor 97 and a capacitor 98, controls high-frequency noise pulses. In order for integrated circuit 1 (ICI) to receive a low level pulse at pin 17, the signal level on line 27 must go low (go to V / 2) for at least half a second before the low level pulse is recognized as a clock signal for ICI. The voltage level on line 110 is compared to the voltage level on line 99, which is tapped from the mains voltage (on lines 27, 28) and serves as a reference signal to determine whether the clock signal is high or low. The use of this reference signal compensates for large fluctuations in the mains voltage. In the exemplary embodiment shown, the system functions precisely despite fluctuations in the mains voltage

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from 15-30 V, i.e. a voltage change of 2: 1.

Other input signals are applied to the integrated circuit ICI from the on-off switches 66 and 67, which are arranged to the left of IC 1. The first arrangement includes switches 1, 5, which represent address selection switches 66. These are set (by optional opening and closing before switching on the system) in order to determine the exclusive address of each transponder. The second arrangement includes switches 6,8, which represent device identification switches 74. These are set according to the special building blocks (not shown) which are individually connected to lines 70 and 71 (Fig. 7) to generate the analog input signals A and B for the integrated circuit.

When the transponder issues an output command, the corresponding signal arrives via one of the lines 76, 78 or 80 in FIG. 8. An output signal on line 80 drives the light-emitting diode 81 connected to line 86. An output signal on line 78 acts on the "connection winding" 101 of the current surge relay 75, the normally open contact group 102 of this relay being closed. An output signal on line 76 excites the erase winding 103 of the relay, the normally closed contact group 104 of the relay being closed. When the transponder's final stage produces a signal on pin 8 over line 79 to drive NPN transistor 100, resistor 89, which in this embodiment is 4.7 kOhms, is connected between lines 85 and 86, and does so Amplitude of the voltage then applied to the control unit smoothes. The operation of the transistor 100 as a function of the transistor control signals on the line 79 is analogous to the opening and closing of the switch S2 in FIG. 3, as explained above in connection with the operation of the transponder. It is apparent that resistor 89 (FIG. 8) corresponds to resistor R3 in the description above of the general operation of the plant.

It should be emphasized that an output command on line 79 to turn on transistor 100 is generated only during the low level portion of each pulse. However, the other control signals for turning on or clearing relay 75 or for lighting LED 81 are only generated during the high-level part of a pulse. This is essential to the invention because the transponder uses energy which is supplied by the control device via lines 27, 28 to act on these modules without tapping into the energy stored in capacitor 91, which acts on the modules shown in FIG. 8. Other components such as the potentiometer 105, the fixed resistor 106, the capacitors 107, 108 are expedient in connection with the integrated circuit 1.

A general block diagram of the integrated circuit is shown in FIG. 9, a functional description of this circuit follows. The pulses of each group, which are applied to the transponder, pass via a line 110 to the input pin 17 of ICI and from there to the clock pulse generator 111. This stage has a conventional pulse shaping circuit, such as a comparator, which also carries the signal voltage level on line 110 the reference voltage level on line 99. The clock pulse generator outputs its output signal to a 2-bit counter 112 and a clock signal identification circuit 113. A reference generator signal is also present on the resistor 106, capacitor 108 and line 93 (FIG. 8). A 5-bit counter 114 (FIG. 9) receives overflow pulses for a line 115 from the 2-bit counter 112. If the incoming pulse remains high for a predetermined period of time (20 ms in the exemplary embodiment), an input occurs

"Stretched" clock identification pulse via a line 117 to a 2/4 line decoder 118. If the incoming pulse remains high for a duration of 80 ms (in this exemplary embodiment), the stage 113 generates an erase pulse on line 116 for both counters 112 and 114 .

The 2-bit counter 112 outputs a "clock decoding output signal" to its output lines 120, 121. This signal primarily identifies which of the various possible commands are to be executed by the transponder. The signal on lines 120, 121 passes to the 2/4 line decoder 118, the 4-channel analog multiplexer 122 and to a switching logic 123. The switching logic offers an external “switching work memory” for two request cycles of this transponder, if the external switch for a duration of less than two request cycles. In this embodiment, a request cycle - the time interval between two successive drive pulses that are generated at the output of stage 131 - lasts three seconds. The storage period for the switching logic 123 thus lasts from 3 to 6 seconds, depending on the exact time in which the polling cycle of the external switch operates. This external switch can be a mechanical instantaneous switch which emits a signal via line 70 and pin 6 to the switching logic. It should be emphasized that despite the presence of this switch and its actuation, the switch logic actuation indicator does not store for subsequent transmission to the 4-channel analog multiplexer 122 unless the corresponding switch identification data is present over three lines connected to pins 18, 19 and 20 are connected. These pin connections are to the device identification switch (ID) 74, as already mentioned. When the device identification switches 74 are combined appropriately to apply the switching logic 123, the stage 123 passes the switch actuation data (on line 70) to the 4-channel analog multiplexer 122.

In the system according to the invention, certain combinations of the device identification switches 74, which are led to the pins 18, 19 and 20, switch on the switching logic 123, i.e. they break the circuit between lines 119 and 129 for 4-channel analog multiplexer 122. In the preferred embodiment, two of the eight possible switch combinations were used to achieve this function. Under these conditions, switching logic 123 receives the signal via line 70, pin 6 and line 119, which signal is processed to generate a voltage for a particular switching state which is passed to multiplexer 122 via line 129. In the other six combinations of the switches connected to the pins 18, 19 and 20, the switching logic 123 effects a straight through connection between the lines 119 and 129.

The mode of operation of the switching logic can be better explained with reference to FIG. 6A. If the device identification signal identifies a two-position switch connected to line 70, the data received via line 119 from the switch must be "translated" or converted to identify one of the three possible switching states, i.e. not connected, open or closed. A temperature sensor connected to line 70 would produce an analog output signal and the device identification signal would lack straight forwarding of this data without conversion in switching logic 123.

A transmitter circuit 124 develops the device identification signal and the calibration signal (reference signal). The identification signals are applied to an 8-channel analog multiplier 126 via a plurality of lines, which are represented by the busbar 120. The labeling

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output signal of the multiplexer 126 reaches the 4-channel analog multiplexer 122 via a line 127, to which the calibration voltage signal from the encoder 124 is also applied via line 73. The multiplexer 122 also has the analog A signal on line 71 and the analog B signal on line 70, both signals passing over lines 119 and 129 when the circuit is closed by logic switch stage 123. The output signal of the multiplexer 122 then passes via a line 128 to the voltage-controlled monostable multivibrator 130, which is provided with connections to a potentiometer 105 and a capacitor 107 in the lower right part of FIG. 8.

The output signals of the 5-bit counter 114 and the input signals of the address selection switches 66 are present on a digital comparison circuit 131 (FIG. 9). When the coincidence between the exclusive transponder address, which is determined by these switches, and the address, which is represented by the pulses transmitted by the counter 114, is recognized, the digital comparator 131 transmits a control signal via a line 132 to the voltage-controlled monostable multivibrator 130 , wherein the drive signal also reaches the 2/4 line decoder 118 via a line 133. If the clock pulse output on line 139 is high, it clears the voltage controlled monostable multivibrator 130. If this clock output signal is low, it generates a second drive signal for stage 130. If both drive signals are present, the voltage controlled monostable multivibrator 130 produces an "excitation output." »On a line 134, which is amplified in the corresponding output driver stage 135 and runs via the output pin connection 8 from ICI. Pin 8 is selected when it reports transponder data back to the control unit. This process is analogous to turning on transistor 100 in FIG. 8 or closing switch S2, as was explained with reference to FIG. 3.

To select another output pin 136 (1, 2, 3, or 4), the 2/4 line decoder 118 must generate a corresponding output signal on one of its four output lines 137. This requires three inputs to decoder 118: 1) a clock decode output on lines 120, 121 which selects the output driver to be driven; 2) a control signal on line 133 corresponding to a "transponder selection signal"; and 3) another drive signal ("stretched clock signal") on line 117, which identifies the command that was issued. The selection of pin 2 indicates that LED 81 is to be controlled. The choice of pin 3 is tantamount to generating a signal on line 78 (FIG. 7) to apply the surge relay, and the choice of pin 4 means generating a signal on line 76 to cancel the surge relay.

The above functional description is sufficient not only to enable the person skilled in the art to develop a special circuit for ICI in FIG. 8, but also to explain the entire functional sequence; furthermore, this description enables the person skilled in the art to carry out the switching operations with different circuits or to regulate different output functions as desired. After the operation and circuit arrangement of the transponder has been explained, consider the way in which the control unit 26 processes the returning data from the transponder and converts it into useful signals and corresponding displays.

Figure 10 shows an ideal pass pulse, i.e. a "stretched" low pulse level

6A. The low pulse level 180 of FIG. 10, like the other pulses in this embodiment, occurs during a period of 32 ms from the falling edge 181 to the rising edge 182 of the low pulse level. The stretched low pulse level 108 has an initial low level portion 183, a rising portion 184 in which the signal rises from level V / 3 to level V / 2, and an end portion 185. Reference line 186 indicates the alarm threshold and lines 187, 188 indicate the range of adjustable sensitivity.

In practice, the actual sensitivity is represented by the difference between line 184 of the pulse and line 186 for the alarm threshold. In a preferred exemplary embodiment, a measuring range of 8 V over 32 ms was plotted, the initial section 183 of the low pulse level representing the analog input value of the control device from the transponder. In practice, however, the returning data is not represented with the ideal waveform of FIG. 10. The various transitions are distorted by the building blocks of the system, resulting in transitions as generally shown in FIG. 11.

Fig. 11 shows an actual pulse with some effects on the line capacitance. The first falling edge 192 of the actual return signal does not fall backwards, but follows a generally logarithmic curve. With this return signal, the end of the analog or information period is shown on the rising section 193, which is also curved and not exactly rectangular. Since these are critical sections that affect the measurement of the section at the V / 3 level, it is desirable to take a vernier or precision measurement during these two transition periods. The units are plotted on the time scale 194 for the “rough range” at intervals of 1 ms. It would be advantageous to introduce a further time scale, which is drawn as the "vernier range" 195, in which the scale units are plotted at closer intervals, such as half or 1/4 ms, in order to enable a more precise measurement of the pulse transitions and thus a more precise derivation the exact analog value represented by the low or zero level of the returning signal. An increased accuracy measurement of this type takes place on different time scales at different time segments according to FIG. 12.

Before starting a measurement, the device is set to level 1 or to the non-measuring mode. At time 0 (0 ms), a measuring device is switched on, which operates during the first two ms of the return pulse in the non-scale range, which is shown as level 3 in FIG. 12. After the time of the initial transition, the meter can operate at a coarser level until the end of the half cycle or 16 ms, which is referred to as level 2. In this example, the alarm threshold is in the following 4 ms, and therefore the meter switches to vernier or precision measurement for this period between 16 and 20 ms. For the rest of the pulse flyback period, i.e. From 20-32 ms, the device can switch back to the rough operating mode measurement and remain there until the end of the period. It can be seen that it is easy for other voltage ranges to be transmitted and different degrees of accuracy in vernier measurement to make changes to the voltage ranges or the measuring intervals.

Fig. 13 shows in simplified form the arrangement in the control unit 26 for processing the return signal from the transponder, which is sent by the comparison elements 51, 52 in order to generate useful data such as "alarm", "fault" etc. The system receives the signal on line 54 when a transponder with a signal of level V / 3 ant5

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words, this signal running over a switch 200, a line 201 and two AND gates 202, 203. The command transmitter 42 regulates the operation of the switch 200 and the two additional three-way switches 204, 205. These switches are mechanically synchronized between the three positions shown. In a preferred embodiment, the effects of the functions represented by switches 200, 204 and 205 are performed under the control of an algorithm stored in the memory of the central unit of the system. The representation with mechanical switches, however, serves to explain the manner in which the signals and pulse trains are routed, tabulated and used in order to generate a correct “response signal” from which useful data are obtained from the corresponding transponders or coupled converters can.

The contacts of the switches 204 and 205 are denoted by 1, 2 and 3 in order to represent the mechanical positions as shown in FIG. 12 in the non-measuring mode 1, the coarse measurement mode 2 and the fine measurement mode 3. An oscillator or pulse generator 206 (FIG. 13) generates a pulse train for the system, which runs over the switches 204, 205 and the AND gates, as long as the signal on line 201 indicates that analog data is coming back from the transponder. The low-level signal 183 of FIG. 10 is present on line 54 on line 201, where the pulse train is controlled by one of the AND gates to a counter then operating in order to generate a "response signal" on line 207.

In particular, the encoder 206 can be a conventional pulse generator that generates a pulse train with a frequency of 4000 Hz in the exemplary embodiment shown. This frequency is chosen in relation to the duration of the return analog signal and other factors, including the desired level of accuracy for the vernier measurement mode. The pulse generator signal goes directly to a quartering circuit 210 via a line 208, and to position 3 for fine counting of the switch 205 via a line 211. The output signal of the quartering circuit 210 is present via a line 212 at the pole 2 of the switch 204, i.e. at the contact applied during the coarse count. The movable contact of the switch 204 is coupled to an input of the AND gate 203 via a line 213, and the movable contact of the switch 205 is connected to a terminal of the AND gate 202 via a line 214. The output signal of the AND gate 202 is applied via a line 215 to the fine counter 216, which adds up the total number of pulses which arrive on the line 215 and outputs a signal to a line 217 for this total. The output signal of the AND gate 203 also reaches the coarse counter 220 via a line 218, which adds the total number of received pulses and outputs a signal for this total sum to its output line 221. This signal is present at a quadrupling stage 222, where it is quadrupled on line 221 and is present on line 223 as a result. The signals on lines 217 and 223 are then added in adder 224, the result being output to line 225. It can be seen that the counting, multiplication, division and addition (or algebraic summation) of the various signals can be carried out in analog or digital processes, the arrangement in this exemplary embodiment being carried out using a digital system. The output signal on line 225 is present at another adder 226, at which a compensation signal is also present via line 227 from compensation stage 228. The exact compensation provided by stage 228 may change as follows

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is explained in more detail. The output of stage 226 on line 207 is thus the response signal representing the length of time that the stretched low pulse level 180 (FIG. 10) of the transponder return signal remains at the low V / 3 level.

The common line 207 (FIG. 13) outputs the response signal via a line 230 to a first comparator 231, on whose output line 232 an alarm-indicating signal is present if it is justified by the value of the response signal io and the setting of the multi-way switch 233. In this exemplary embodiment, this switch can be flipped to three different settings by the stage 234 for adjustable sensitivity, the stage 234 being controlled via a line 235 by a program of the digital system which controls the overall operation and which is stored in a memory (not shown) via a line 236 from a keypad or another data point, not shown, which is coupled to the system. The stored program can change the position of the switch 233 before comparing the response signal for each transponder connected to the system. This enables the assignment of any sensitivity setting to a signaling device in the system. This control of the switch 233 represents the function of the adjustable sensitivity, since the sensitivity of each signaling device can be set from the control panel without switching off the system. By changing the contact positions of switch 233, the number next to the contact indicating the value of alarm threshold 30, the response signal on line 230 must be equal to or greater than this number represented by the setting in order to receive an alarm signal on output line 232 to create. The numbers 65.75 and 85 represent sensitivity thresholds on the scale from zero to 128 35, this scale being obtained by multiplying the return interval of 32 ms by 4. The reason for this follows from the functional description below.

The response signal on line 207 is also present via line 240 to another comparison element 241, on which another reference input signal is also present again via line 242. The comparator is switched so that a fault indicating signal is generated on the output line 243 when the response signal on line 207 is less than or equal to the reference signal on line 242.

For the description of the mode of operation, it is initially assumed that the control unit 26 has instructed an addressed transponder to return the data, the command transmitter 42 in FIG. 13 thus moving the switch 200 into the position shown at the beginning of the return period. The switches 204, 205 are set to contact 3 for the fine counting. Now the pulse generator 206 controls signals via the line 211, the switch 205 and the line 214 to an input of the AND gate 202. As soon as the fourth or low 55 pulse level begins, the other input signal is present at this AND gate via line 201 from comparator 51, so that the pulse train runs over line 215 and is stored in counter 216. Assuming that the falling edge 192 (FIG. 11) of the response pulse reaches 60 the level V / 3 after 1.5 ms or after 6 counting steps on the time scale 195, then the remaining two pulses or counts arrive via the AND gate 202 (FIG. 13) to the counter 216. This is because the command transmitter 42 holds the switches 204, 205 in the 65 position 3 for the first two ms of the flyback period, whereupon the switch contacts are switched to the position 2 for the coarse count. Thus, the AND gate 202 is locked out of the circuit and the AND gate 203 is switched to the stage 210 via the switch 204

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coupled. The pulse train of the pulse generator 206 is thus reduced in the stage 210 and is applied to the AND gate 203 via the line 212, the switch 204 and the line 213. The pulses now follow at 1000 Hz or a frequency of one pulse per ms as shown on the time scale 194 of FIG. 11. Because switches 204, 205 remain in position during the interval between 2 and 16 ms, 14 pulses are turned on via line 218 and added in counter 220. This number is multiplied in step 222 and results in a value of 56 on line 223, which is added in step 224 to the value (2) previously received via line 217. At this point (16 ms), the adder 224 stores a count of 58 and the switches 204, 205 are switched back to position 3 for the fine count.

Assuming that the transition 193 (FIG. 11) takes place at 18 ms, then 8 pulses from the pulse generator via the switch 205 and the AND gate 202 to the fine counter 216 are controlled in the period between 16 and 18 ms, which saves them, whereupon this count is fed via line 217 in adder 224. These eight pulses are added to the previous total 58, whereupon the total in the adder 224 is 66. At the time of 18 ms, there is no longer a control signal from line 54 on line 201. After 20 ms (from time zero), the switches 204, 205 are switched back to position 2 for the coarse count, but no control signal is now present to control the pulses through the AND gate 202 to the coarse counter. The signal on line 225 now passes to adder 226.

The first result can now also be modified with compensation level 228. For example, if the last query of the particular transponder showed that a "reference voltage" has increased from 4.0 V to 4.06 due to component aging or other long-term system changes, the result on line 225 may be the subtraction of 1 from the Count 66 can be changed to give a new count, namely 65, for comparison with the alarm threshold level and similar applications at other processing levels. Therefore, a count of 65 is assumed to represent the response signal on line 207 that is passed to comparators 231, 241.

The comparator 231 is guided via the switch 233 to a voltage level of relatively low sensitivity 65, which represents 65/128 of 8 V or approximately 4.06 V. Since the signal on line 230 (65 in total) is the same as reference signal 65 at the other input of comparator 231, an output alarm signal is now generated. The comparator 241 determines that 65 is greater than a reference input voltage 35 (for 2.19 V), and therefore no interference signal is generated on line 243. Further processing stages are described in more detail with reference to FIG. 15. However, it should be emphasized that the system of FIG. 13 converts the analog signal on line 201 into a digital response signal on line 207 with an extremely high degree of accuracy, even if the fine counting method only takes 2 ms when the response signal is triggered and for 4 ms in the Is used near the middle of the return time. In a broader sense, a vernier measurement at a higher frequency than the reference frequency is used for a limited period of time in order to achieve an accurate and effective measurement over a much longer period of time.

14 shows a system for generating a “response signal” on line 207 from one of several areas in which various transponders and converters are arranged. This area generates a data describing signal on its corresponding line

41A, 41,41B or 4IN. This process is analogous to the different line pairs 17 controlled by a plurality of control units 26. The various switching functions of FIGS. 13, 14 and 15 are shown here as being regulated by a command transmitter, i.e. regulated by a central unit with a corresponding program and a plurality of control units 26. In the multiple areas of FIG. 14, the corresponding data are analyzed and evaluated in multiple channels, whereupon various “response signals” are present on the corresponding output lines 251, 252, 253 and 254, which represent the corresponding state of the respective area. The command transmitter 250 then acts on a switch 255 for the serial connection to various output lines 251, 254 and at one time only generates a “response signal” on the line 207. It can be seen that the routing of the individual area signals is used to control the program, which is stored in the control unit or is assigned to the central unit, not shown, in order to create a workflow which represents a functional replacement image of the switch arrangement shown in FIG. 14.

15 shows how the "response signal" is distributed on the busbar 207 in order to feed the "response data" to various processing stages. The processing of this data in order to obtain the "alarm" and "fault signal" has already been described. 15, a sixteenth divider stage 260 is connected to line 207. Since 128 counting steps represent a voltage amplitude of 8 V in this exemplary embodiment, dividing 8 by 128 (as in the sixteenth divider stage 260) gives a ratio for converting the response signal on line 207 into a signal! (on line 261), which represents the actual voltage of the transponder. For example, a response signal value of 67 would be divided in stage 260, with an output value of 4.2, i.e. 4.2 V would appear on line 261. If a Zener diode or other device is used to generate a 4.0 V calibration voltage across the transducer, this results in a 64 value response signal on line 207 which is divided down in stage 260 by a 4.0 calibration voltage V on line 261. A further sixteenth divider stage 262 is connected via a line 263 to the movable contact of the switch 233, at which the selected alarm threshold voltage is present. Assume switch 233 is set to the center or the middle threshold voltage, which is identified by a count of 75 in the drawing. The value runs over line 263 and is divided down in stage 262, resulting in a value of approximately 4.7 V on line 264, the input connection to adder 265. If the voltage of 4.2 V is present across lines 261, 266 at the negative input of stage 265, it is summed algebraically, subtracting 4.2 V from 4.7 V and the result of 0.5 V on the output line 267 is present. The result thus represents a measure of the converter sensitivity, since it shows how "far" the converter is "away" from the alarm threshold voltage. If the voltage increases by a further 0.5 V, the actual voltage reaches the alarm threshold and generates an alarm signal on line 232. By monitoring a long-term change in the sensitivity value on line 267, the protocol of the control unit can make the changes due to component aging , Dust and similar defects. This sensitivity value on line 267 represents an important measurement and provides information on the control unit that was not previously available.

A further algebraic summing stage 270 is connected to line 207, on which the “response signal” from

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the input line 271 is present. A memory 272 is also routed to busbar 270 via line 273. If the device is originally installed, the target calibration signal from the individual transducers returns via its transponder. The original calibration signal is stored in stage 272 and forms a fixed point for later measurements. The signal is then fed back to stage 270 via lines 207, 271 in the “Sunday morning query”, a measurement that is carried out at 2:00 am on Sunday morning when the workload is low. The resulting compensation signal on a line 275 is a measure of the long-term changes in the circuit, the electrical lines and other variables which affect the generation and transmission of the calibration voltage. Thus, the signals on lines 275 and 308 (or part of these lines) can be used to modify the data, for example to amplify or attenuate the response signal when the compensation signals change, while maintaining the normal operational sensitivity of the system.

Stage 400 is connected to stage 270 via line 401, receiving a signal for the extent of the change in the original calibration signal. A signal for the reference level is also present at the stage 400 via a line 402, and if the calibration change signal exceeds the reference level, a “maintenance request signal” is generated on a line 403. The device identification signal is obtained by sending the "response signal" on line 207 over line 280 where it is compared by a plurality of comparators 281-288, only the first and last of which are shown. Device identification switches 74 are shown generally in FIG. 7 and in detail in FIG. 8. The switch settings are converted in multiplexer 126 (FIG. 9) to a switch identification signal on line 127 and then forwarded to the controller. Thus, the signal on line 280 (FIG. 15) represents one of eight different values, the exact value being determined by comparators 281-188. For example, a "Type 1" signal can represent a smoke alarm device designed as an ion probe, and if the signal on line 280 lies in the range determined by the input signals applied via the powers 290, 291 from the comparator 281, then the output signal present on line 292 shows indicates that the connected device is a «Type 1» unit. In this way, the voltages generated by the various combinations of the settings of the device identification switches are decoded and are used on the control device to identify the particular device, which then sends back data for its assigned transponder.

The expression "Sunday morning service" is used to indicate that a serial interrogation of the transponders and storage of the returned data has been carried out, the interrogation being carried out at a frequency which is considerably lower than the normal interrogation frequency and preferably when the premises are practically not are occupied and therefore calm. At these times, the conditions and conditions of the monitored areas have stabilized, and a trial query at this time is used to obtain reference data. For example, the return voltage of a converter can be received and then compared to the initial response voltage of the converter to determine changes in this response and return signal.

The three stages 300, 301 and 302 shown below in FIG. 15

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only serve for the less frequent query, the "Sunday morning query". The original converter response received on the first Sunday morning query after the system was switched on is sent via line 303 to stage 300, where it is stored, this value then not being changed. For each subsequent weekly query, the response on line 207 on line 304 goes to algebraic adder 301, where the original transducer response (from stage 300) is subtracted and the result is available as an output on line 305. Stage 302 is a simple comparator to determine whether the amplitude of the signal on line 305 - and thus the magnitude of the change in the transducer response - falls within an acceptable range. If the magnitude of the signal change is greater than an acceptable range, a signal is generated on line 307 indicating that maintenance is required. This signal can be an optical signal, such as a control lamp in a control panel or an acoustic signal that changes in a certain way, but it can also be the physical deflection of a license plate or a marker or another display device . The exact device and the method for using the "maintenance required" signal is not essential to the invention. However, it should be noted that this is an extremely beneficial and useful signal because it alerts the user of the equipment to the need for maintenance before a malfunction or error signal can occur.

30 The optional remote calibration of all transponders is also advantageous. It can be carried out for every transponder by changing the five address selection switches (21-25, Fig. 8 and 9) so that they store the address 31. The control unit then checks the calibration voltage running back from this transponder and, if this lies within acceptable limits, it indicates this by the LED on the transponder lighting up. Other operations, such as setting the relay, can be used to indicate the acceptable range of the calibration voltage. If the returning calibration signal is not within the specified limit values, a potentiometer (105, Fig. 8 and 9) is readjusted until the calibration is correct and this is reported by the LED. After checking the correct calibration, the address selection switches are returned to their 45 original settings.

Fig. 16 shows a general arrangement of a class A system with a plurality of transponders 25a and 25b which are excited via the loop. The control unit 26 has two lines 311, 312, via which the signals over 50 are transmitted and received. The line 311 is provided with a screw terminal 313 and a line section 314. The line 311 is also connected via a normally open contact group 315 to a further screw terminal 316 which is guided 55 to another line section 317. Sections 314, 317 are connected to one another by a short line section 318 and thus form an electrical circuit from line 311, via screw terminal 313, line sections 314, 318, 317 and screw terminal 316.

60 The line 312 is connected to the power line section 321 via another screw terminal 320. The line 312 is also connected to a line segment 324 via a normally open contact group 322 and a further screw terminal 323. A short section 325 of the power line 65 closes the electrical circuit between the segments 321 and 324. Between the terminals 316 and 323 a resistor 326 is connected, which fulfills the function of the resistor R2 of FIG. 3.

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In normal operation, it is obvious that an excitation voltage difference and the signals can be applied to all transponders via lines 311, 312. For example, if the voltage on line 311 is positive with respect to the voltage on line 312, current flows from line 311 through terminal 313, line voltage sections 314, 318 and 317, transponders 25a and 25b, line sections 324, 325 and 321 and that Screw terminal 320 for line 312. However, suppose that an interruption occurred at point 327 in line section 317. This would mean that there would no longer be a transponder in the loop described above. The transponders 25b still receive voltage, but are not connected to the resistor 326. According to the normal operation of class A, the contact groups 315 and 322 would now close (via devices which are not shown but are generally known). Despite the interruption, the three transponders 25b on the right in FIG. 16 are now connected again to the resistor 326, and the transponders 25a are now activated when the current from the line 311 via a contact group 315, the screw terminal 316, the line section 317 to the transponders 25a flows. In previous arrangements, the contact groups were closed, with the assumption that the transponders were put back into operation by this operation. However, the invention has advantages that were not achievable with the earlier Class A plants.

For operation according to class A with the invention, the contact groups 312, 322 are closed, the transponders are called again and the addresses of the transponders reporting back are registered. If all transponders are now reluctant, the correct operation of the system would be resumed by using the class A circuit. This shows that there was only one break on one or both sides of the loop. This proof that the system is fully functional again,

could not be achieved with the earlier plants. Therefore, the operation of the invention with a Class A system is a significant advantage over the previous devices.

There may also be two or more breaks in the line loop including sections 314, 318 and 317, or in the other loop. With the earlier Class A systems, the normally open contact groups 315.322 would close. With these earlier arrangements, however, there is no clear knowledge that the contacts or other class A circuits have not been closed to return the system to normal and that the transponders are not working. In the case of the invention, these transponders are queried, and from the non-arriving answer it follows that the system does not work as a result of a multiple interruption, the transponders which are still not responding being specifically and individually identified.

To illustrate the wiring according to class B, FIG. 16 is modified as follows. The line sections 314 and 318 are omitted and are replaced by a bridge 319, which connects the screw terminals 313 and 316 to one another. In the other loop as well, the line sections 321 and 325 are removed and replaced by a bypass 320. In the case of a single interruption 327, the location of the interruption can be determined as being between two special signaling devices. In the modified system of FIG. 16, the control device calls the system and registers the addresses of the non-responding transponders. If all the transponders in the loop are addressed in sequence, the interruption between the last responding transponder and the first non-responding transponder is located. The interruption can also be located with non-serial addressed transponders with additional data.

The term “control device” used in the description and in the claims applies not only to the control device 26 of FIG. 3, but also to the central unit and its corresponding program. 17 shows the connection of a central unit 330 via a busbar 331 to a plurality of control devices 26, 26a, up to 26n. Several control units 26, 26a ... 26n can jointly use the memory processing capability of a single central unit. In addition, input devices 332, such as a keypad, can be used to input data to the central processing unit, e.g. a request for a response from a particular transponder in a particular area. Corresponding output devices 333, such as a printer, loudspeaker, cathode ray tube and other arrangement, can be provided in order to display the state of the data processed by the central processing unit. It is thus emphasized again that the expression “control device” not only includes the actual control circuits, but also the central unit, at least on a shared basis. It can be seen that a central unit can be provided on a micro-module with an integrated circuit together with a compact control unit.

According to this definition of the control unit, the considerable versatility that such a control unit lends to the system according to the invention and the wide range of data of the output signals of the control unit must be pointed out. This will be explained in more detail with reference to FIGS. 18, 19A-19F and 20A-20F. Although these waveforms are not exactly to scale, a 2.5 cm measurement on the abscissa of each waveform represents a period of 32 ms.

In the first representation of FIG. 18, the five pulses shown have four pulses of a pulse group for the data and a specific transponder address which are related to the four pulse groups of FIGS. 6A-6C, and a long pulse like the signal at the address 31 in Fig. 4. The low level of the pulses in Fig. 18 represents the state when the control unit switch S1 is broken (Fig. 3), and the high amplitude shows the state when the S1 is closed. The rise and fall of each pulse indicates the closure or interruption of switch S1.

In Fig. 18, the first pulse rises at time to when switch S1 closes, thereby transmitting certain data. Closing the switch and the subsequent pulse increase commands the previously reporting transponder to end its transmission and tells each transponder to increase its corresponding counter. This means that the individual pulses and thereby also pulse groups can be counted so that the transponders addressed one after the other recognize their own individual addresses. After S1 has closed, the command is given if the switch remains closed for a specified minimum time (shown as a duration between po and t2) that the transponder has its output No. 1 switch on. In the system described, this is represented by a signal at output pin 1 of output control stage 135 in FIG. 9. The other output pins 2-4 apply to the commands in the second, third and fourth pulses of Fig. 18. Since the pin S1 of the output control stage is not being used at this time, the fact that by stretching the first high level pulse causes over t? produces no initial effect. At time t3, S1 is interrupted, the pulse goes low, and this event reports the addressed transponder its output signal No. 1 to end (by

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Switching off the signal from pin 1 in Fig. 9) and to start transmitting its calibration data. If the pulse were low at time ti, this would indicate that output No. 1 of the addressed transponder would not have to be switched off.

If the switch S1 in the control unit remains open, the duration of the low-level signals t3 and t4 can be up to 32 ms after time t3, because 32 ms is the time period selected in the preferred exemplary embodiment.

Of course, the low-level signal is continuously tapped to determine whether a transition is taking place and thus to display the actual value of the calibration data that is going back to the control unit. If this requests a return of the calibration data from the addressed transponder, S1 is closed again after only one or two ms, so that the time span between t3 and t4 would be 1 or 2 ms. It is obvious that each pulse rise and fall of the pulse group generates data or commands for the addressed transponder or for all transponders.

At time t4, S1 is closed, the pulse becoming high and either ending the transmission of calibration data or preventing it, which increases the counter of all transponders. Switch S1 opens again at time ts, the pulse becoming low before time (t6) at which a high level pulse would have commanded the transponder to apply its output # 2. In this case, this would have meant controlling the pin 2 of the control arrangement 135 (FIG. 9) to a high level and leaving the light-emitting diode 81 (FIGS. 7 and 8) illuminated. However, the pulse became low at time ts, which means that there is no switching process at output No. 2 of the LED. In the period between ts and ts, the transponder can return the identification data. If the pulse had become high shortly after the time ts, the transponder could not return this data.

At time ts, S1 closes again, the pulse becoming high and the transmission of the identification data terminated, whereupon all counters are increased. The third pulse remains high only until ts, with S1 open. At this time, S1 is opened before the time (tio) up to which the high level pulse must be extended to command the transponder to control pin 3 of the control assembly 135 high, thereby setting the relay 75 (FIG. 7) is ordered. Thus opening switch S1 at time t9 is practically a command not to apply the relay. The pulse remains low until ti2, that is for an extended period in which the transponder can return data corresponding to analog input 1 on line 70 in FIGS. 7-9. The analog value of this signal is obtained in the transponder, as was explained above with reference to FIGS. 11-15. At time ti2, switch S1 closes again, as a result of which the pulse level in FIG. 18 rises, the response from the responding transponder being ended and all counters being increased.

The fourth pulse must remain high for a certain period of time, which is shown as the path between ti2 and ti4, so that the transponder can act on its output No. 4 and thus delete the relay. If the pulse were low at time ti3, the transponder would not delete the relay. However, the pulse remained high through ti4 to tis, and therefore the command is issued and the relay is cleared. Between times tis and ti6, the transponder tries to return the data of its second analog device, which is present via line 71 (FIGS. 7-9). 18, however, since it is assumed that the switch S1 after only 1 or 2 ms

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closes, the transponder is not informed to transmit the data of its second analog device. At time ti6, S1 closes again, the pulse level indicating and the transmission of analog data 2 prevented, all counters being increased.

The four pulses described above represent a group of pulses that address a single transponder. Therefore, at time ti6, the address of the next transponder in the address sequence (which does not necessarily represent the next in the physical arrangement) is initiated. The fifth pulse remains low beyond time t22. If the pulse had become low by interrupting switch S1 at time ti7, it would have commanded the transponder to output No. 1

15 not to act. Since it remains high beyond tis, the command is given to control output No. 1. In this exemplary embodiment, the timing circuit taps off at time ti9 that output No. 1 is to be switched off. The pulse remains beyond t2i and t22

20 high level, with all transponders recognizing at time t22 that this extended high level pulse is an erase pulse, as a result of which all counters in all transponders are deleted. This description makes the extraordinary amount of data and commands evident 25 that are applied to a single pulse group in the two-way traffic system according to the invention.

Figures 19A-19F show a pulse group from the controller in Figure 19A and the transponder's response or non-response to each pulse of the group of Figures 19B-30 19E. 19B-19E show the signals from the corresponding output pins 8 and 1-4 on the right side of IC 1 in FIG. 8 and the right side of the output control or driver arrangement 135 of FIG. 9. The designation "encoder 19B on the right shows that the 35 pin 8 goes high when the waveform in 19B goes high and tries to transmit data from the transponder to the controller. The other four outputs show the responses given depending on the command in Fig. 19A.

40 In detail, FIG. 19A shows that S1 is closed at time to and the first pulse is triggered. S1 remains closed until ti, this period being too short to generate a return signal at output pin 1, switch S1 opening at ti. At this point, pin 8 45 goes high, with the transponder attempting feedback as shown by pulse 340 in FIG. 19B. At time t2, however, S1 closes again to end the first command, and when the pulse of the control device goes high, the pulse 340 on the transponder is switched off, because of the short duration of the first command, i.e. Because of the high level section between to and ti, no control command was given, so there is no change in the output signal at pin 1 as shown in Fig. 19C.

At time t2, switch S1 closes and, beyond 55, the minimum time t3 remains closed, which is required for a command to output 2 in order to become high. Accordingly, the output of pin 2 becomes high as shown by the rising edge of pulse 341 of FIG. 19D. The pulse 341 on the output pin 2 serves to switch on the light-emitting diode 81. The latter is thus activated between t3 and t4, while the switch S1 in the control unit remains closed. Sl opens at t4, pulse 341 is switched off and the LED goes out. Now the transponder tries to return data, see pulse 342 in 65 Fig. 19B. However, the time period between t4 and ts is too short for the return of the identification data, and the pulse 342 is switched off when the switch S1 closes again at the time ts.

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The third pulse in the group of FIG. 19A remains high for a short period that is too short to trigger a drive command on output pin 3. This maintains the low level waveform on pin 3 (Fig. 19E). At time t6, S1 opens and the third pulse goes low (FIG. 19A) but not as low as the previous low pulse level of the pulse group. This is because the third low pulse level now spans the time span in which the first analog signal is returned from a connected device. This low level with reduced amplitude indicates that no such device is connected to the responding transponder. If there were a device that generates a zero level signal, the low level third pulse would be at the same level as the previous low level.

At time t7, S1 closes, which initiates the fourth pulse of the group. This pulse remains high beyond ts and indicates a command that also makes the output pin 4 high and performs the corresponding operation. In this case, the process is to cancel the associated relay, and at time ts the rising edge of pulse 343 (FIG. 19F) is generated at pin 4, which provides for this cancellation. Pulse 343 remains high up to when S1 in the control unit opens again to delete the command, whereby pulse 343 is also deleted at the same time. The fourth low pulse level begins at t9, the prolongation of this low pulse level making pin 8 high, which remains high and returns data from the second analog device. The pin 8 becomes low again at the same time as the fourth low pulse level changes, and this state remains until tn. At ti i the pulse group described is deleted and the next pulse group is initiated.

From the description with reference to FIGS. 18 and 19A-F, the versatility of the system is evident in the transmission of commands and the recording of data. However, it can be seen that the system can also transmit other data by regulating the closing time of S1, and thus also the duration of the high pulse level of the control unit, with various data from the transponders or the associated converters also being present. An example of the transmission of such additional data is shown in FIGS. 19A and 19D. Because the second pulse remains high for more than 20 ms (the predetermined time in this embodiment), which is shown at t3, the light emitting diode lights up. The pulse 341 shows that the duration of the lighting up lasted approximately another 20 ms. Of course, pulse 341 could be shortened or extended over 20 ms to transmit various data. This means that the duration of such a pulse can itself mean information either for the devices connected to the transponder or for the monitoring personnel of the transponder.

This regulation of the switch S1 to control data is shown in FIGS. 20A-20F. The controller output pulses in Fig. 20A are again a four pulse group. The first pulse becomes high at time to and remains high above ti when S1 is closed, i.e. for the minimum time to make output pin 1 high and initiate data transmission by generating the rising edge of pulse 345. This pulse remains high until time tz when S1 in the control unit opens again and deletes pulse 345 at time t2. This represents a pulse duration of approximately 12 ms, which is a command to perform a specific function or a representation of a

Analog values can be according to the pulse duration.

Sl opens at time t2, whereupon output pin 8 goes high when the transponder tries to report back. However, S1 closes after only four ms, triggering the second pulse of the transmission group and deleting the intended output signal of the transponder, since pin 8 goes low at time t3.

The second pulse remains high, since S1 remains closed beyond t4, the minimum time for executing a function command to send the data to output 2 of the transponder. The rising edge of pulse 346 of FIG. 20D is generated at time t4 and this pulse remains high until time ts when switch S1 in the control unit reopens. This opening of Sl clears pulse 346, causing pin 8 to go high if the transponder tries to answer, but this attempt is cleared at t6 if Sl closes. The generation of pulse 346 thus represents a data pulse of 32 ms, which is sent to the addressed transponder.

The third pulse remains high beyond t7 when the rising edge of pulse 347 is generated, with output pin 3 becoming high. The duration of this pulse between t7 and ts marks an interval of 8 ms,

whereupon interrupts at ts to cancel this pulse. The transponder tries its answers between ts and t9, since no device for forwarding the analog signal 1 is connected.

The fourth control unit pulse is triggered at t9, since S1 closes again and remains closed beyond tio,

whereupon the output pin 4 is high and the pulse 348 is triggered. Pin 4 remains high until tu when S1 in the control unit interrupts in order to cancel pulse 348 after a data transmission of 40 ms. At time tu, output pin 8 goes high, the transponder returning pulse 350 to time ti: at which the transition to the fourth low pulse level of the group takes place. This last pulse of the group is deleted at ti3, the counters are increased and the next transponder begins to respond to the pulse group.

With a two-way two-way system, this system offers many advantages over the previous systems. For the description and the claims, a two-way oncoming traffic system is a device in which the commands or data are transmitted from a source (control device) to a receiver (transponder) via a connection path such as two lines, and data or switching status data optionally reach the source from the receiver via the same connection path. The term “oncoming traffic” describes a connection or traffic system in which the commands or data are combined in a pulse group, which consists of more than one pulse, and is transmitted from the source to the receiver, with selected data or status data always being sent by the receiver are transmitted to the source before the one pulse group is deleted until the source ends the retransmission of the receiver with a simultaneous canceling transmission. The receiver does not transmit any further impulses, but changes one (or more) of the impulses of the source, with this change corresponding data being implemented by the source. The exclusive two-way traffic system according to the invention has many significant advantages over known arrangements. Among the outstanding features are:

1. vernier measurement in the control unit to increase the accuracy of the response signal;

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2. Accurate decoding of the data from the returning transponder, even if another transponder has a malfunction at the same time;

3. decoding the response signal to (1) recover data from an associated transducer, (2) receive calibration data from the responding transponder, or (3) receive tag data from the responding transponder;

4. Compensation of the response signals of the transponder and the converter;

5. Automatic maintenance request when the size of a compensation signal reaches a predetermined level;

6. Continuous determination of the transducer sensitivity on the control unit, which is arranged away from it;

7. Use the transducer sensitivity measurement to monitor all devices and to determine - on the control unit - when alarm and fault conditions occur;

8.Sensitivity setting of the remotely located converter on the control unit, which can be continuously and automatically controlled (e.g. by a stored program related to the time of day or day of the week) or manually (via a keypad). The different converters

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can be set to the same or different thresholds, which thresholds can be changed by some or all transducers at any time;

9. Power supply for the transponder and converter from the control unit via the same two lines,

which transmit the data;

10. Exclusive monitoring of Class A and B systems.

The monitoring system is not limited to a system with ion probes, darkening detectors, measuring devices for the rate of temperature rise or another special type of measuring device. Instead, the facility contains systems for reporting impending or existing fires.

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For the claims, the term “connected” means a direct voltage connection between two components with practically zero direct current resistance between them. The term “coupled” indicates a functional relationship between two building blocks, whereby other elements connected between the two building blocks may be described as “coupled” or “inter-coupled”.

B

11 sheets of drawings

Claims (10)

660927 PATENT CLAIMS 1.Monitoring system with a central unit and a plurality of addressable signaling units connected to it via a signal rail, each having a sensor which responds to a parameter to be monitored, in which a) the central unit has an addressing circuit for generating addressing signals in a predetermined sequence and one with those of the signaling signals generated to the signaling units has an evaluation circuit, the latter containing a signaling signal setpoint memory, b) the signaling units each have: an activation circuit which compares an addressing signal assigned to the respective signaling unit and the addressing signals received via the signal rail and generates an activation signal if they match, and an output circuit which can be switched on by the latter and which is connected on the output side to the signal rail and on the input side to the sensor , characterized in that c) new signal signal setpoints are read into the signal signal setpoint memory at predetermined times using the actual measurement signals then present. 2.Monitoring system with a central unit and a plurality of addressable signaling units connected to it via a signal rail, each of which has a sensor which responds to a parameter to be monitored, in which a) the central unit has an addressing circuit for generating addressing signals in a predetermined sequence and one with those of the signaling signals generated to the signaling units has an evaluation circuit, the latter containing a signaling signal setpoint memory, b) the signaling units each have: an activation circuit which compares an addressing signal assigned to the respective signaling unit and the addressing signals received via the signal rail and generates an activation signal if they match, and an output circuit which can be switched on by the latter and which is connected on the output side to the signal rail and on the input side to the sensor , characterized in that c) the sensors are adjustable in their sensitivity, and d) the signaling units (25) each contain sensitivity actuators (124) activated by the central unit (26) at predetermined times. 3, characterized in that the responsiveness continuously and automatically at the central unit (26), e.g. is controlled by a stored program. 3. Monitoring system according to claim 1 or 2, characterized in that the central unit (26) comprises a device (233) with which the stored setpoint signal can be set so that the response sensitivity of the sensor can be set; even if this is connected to the signal rail (27, 28) at a location remote from the central unit (26). 4, characterized by a device (300) for storing an output measurement signal, which was reported back when the system was started up by the sensor of a signaling unit (25), and by a subtraction circuit (301), which measures the difference between the output signal and determined the current message signal and provides a sensor compensation signal (308). 4. Monitoring system according to one of claims 1 to 5, characterized in that at least one reporting unit (25) has a device (43) to report reference data to the central unit (26) depending on the calibration of the reporting unit (25), the central unit (26) having devices (260, 261) in order to receive the data corresponding to the calibration data feedback from the addressed reporting unit (25) and to display the working accuracy of the system. 5. Monitoring system according to one of claims 1 to 6. Monitoring system according to one of claims 1 to 7. Monitoring system according to claim 6, characterized in that the feedback reporting unit (25) has a display device (81), and the central unit (26) contains a device (400) which confirms when a reported calibration response signal lies within predetermined limit values, and that with such confirmation, the display device (81) is energized to indicate that the calibration response signal is within the target limit values. 8. Monitoring system according to claim 7, characterized in that the signaling unit (25) contains an adjustable component (105) which effects a change in the calibration response signal, whereby the latter can be adjusted on the signaling unit (25) until it lies within the target limit values what can be read on the display device (81) of the signaling unit (25). 9. Monitoring system according to one of claims 1 to 8, characterized in that a device (272) in the central unit (26) stores the calibration response data and that an adder (270) compares the following data with the stored calibration response data and depending on the comparison result Compensation signal for the addressed reporting unit (25) generates (275). 10. Monitoring system according to claim 9, characterized in that a comparator (302 or 304) is connected to the adder (301 or 270) and generates an output signal when the compensation signal is greater than a desired level.