DE4427691C1 - Control circuit with slave state monitor for community antenna system - Google Patents

Abstract

Several slave circuits (3) are connected in series to a master circuit (1) by means of a bus system (5) incorporating a daisy-chain (7) and transmission and reception lines (9).The master circuit terminates the daisy-chain in which a mechanical switch (13) across the input (E) and output (A) of each slave circuit is opened automatically when the slave is switched-in. The input to the most remote slave (3.1) is set permanently at the higher logic level.

Description

The invention relates to a control circuit with a status evaluation for slave circuits with a Master circuit work together, especially for one central community antenna processing system, for Head ends for the cable feed or for repeaters station for radio telephones according to the preamble of claim ches 1.

Using community antenna processing systems and Headends are known to be a variety of homes openings, offices etc. with radio and television programs supplies that are not only terrestrial but also over To be broadcast on satellite.

In doing so, those received by a satellite antenna Satellite programs based on their polarization Input distribution panels placed between those and one Output collector individual channel strips are switched that  via a communication bus from a processor control first control unit can be controlled and by means of which the individual programs broadcast via satellite certain channels are laid.

In the event of service or when replacing a channel strip, in conventional systems all settings via Operator-friendly, centrally or directly on the channel strip can be entered.

In a gat known from DE 92 14 381 U1 central controller antenna processing systems, it is known to be a central operator unit to ver as master circuit turn over a bus structure with a variety of individual channel strips connected as so-called slave circuits is. In this well-known community antenna processing processing system, it is possible to use similar channel strips in their access logic to address one after the other in order to Switching on the mains, service operations or at automatically assign addresses to a new configuration. Address allocation can be used for a specific Channel strip correctly assigned to certain operating data in the Memory of the corresponding channel strip.

This provides the prerequisite for that when exchanging no new parameters are entered for a channel strip got to. All essential data can be stored in the central memory the central operator unit, where then only those for the individual channel strips autonomous operation of the specific channel strip required Data are stored.

This previously known circuit arrangement uses a interrupted control line or an interrupted one Control line bus like a "chain line". Here  The individual channel strips are addressed via. The relevant information from the central tax office unit to the individual channel strips or the answer blocks from the individual channel strip to the central control unit via a bidirectional or a first outbound and a second inbound information bus take place, the connection between the central tax unit and the individual channel strips.

The individual also as slave units or slave switching circles designated channel strips is in each case an over bridging device serving switch for the chain assigned. This is with the channel strip inserted interrupted, so that a chain between the individual NEN channel strips are each such that the output one channel strip with the entrance of a next one switched channel strip is connected. When removing one Channel strip is then the respective channel concerned train associated switch automatically closed, so that the free slot for the channel strip in question the closed switch is bridged.

The structure of this known control circuit is such that zen serving as the master circuit central operator unit controlled the first channel strip the output of which is then the input of the next Kanalzuges and the thereby formed, in the manner of a Selection line acting chain line is connected.

Although this basic structure of the known tax circuit has proven itself, it is the task of the present the invention, this known control circuit be in terms of functional reliability, speed and overall construction to improve still further or an improved tax creation process.  

The task is according to the invention in accordance with solved claim 1 specified features. Favorable off designs of the invention are in the subclaims specified.

In the present invention, surprising and amazing way with comparatively little effort a significant improvement over the conventional one Control device created.

According to the invention, the overall structure is in contrast to the prior art in such a way that the master switch central operator or control unit serving as a circuit arranged at the beginning but at the end of the chain line is. In other words, each one is a channel strip serving first slave control circuit to central operator unit at the opposite end of the chain line switched. This causes a switchover to the closed position stood in the working state, for example about the Sen De and reception readiness of a channel strip in each case consecutively from the most distant channel strip to the the last one closest to the central operator unit Channel strip. This has the main advantage that the Emp catch a corresponding signal from the output of the central operator unit in the chain line last upstream channel strip always means that all channels trains polled and a corresponding polling cycle was completed det. In contrast, in the prior art a sepa rate return line should be provided to the end of an Ab ask all channel strips back to the central operator to report back. This requires in the prior art not just an additional fourth line, but above it also a time monitor. Because it must also be a sufficient safety time interval observed and ge be maintained to always ensure that a entire query cycle had expired. For example  only one or two channel strips from a large number of provided channel strips a readiness to send signali to provide certain information and data to the zen to deliver central operator unit, this also required always adhering to a corresponding time tax circuit.

The invention is described below with reference to drawings explained in more detail. The individual shows:

Figure 1 is a schematic diagram of a first embodiment of the invention with mechanical switches provided in the chain line's.

Fig. 2 is a circuit diagram corresponding to Figure 1, in which in the chain line not mechanically operated, but by means of a resistor diode arrangement, we are arranged electrically switching switches; and

Fig. 3 shows another modified Ausführungsbei game, in which the mechanical switches provided in Fig. 1 are replaced by a gate arrangement.

In Fig. 1, a first embodiment of the control circuit is shown. It comprises a master circuit 1 and a plurality of slave circuits 3 . The master circuit serving in the case of a central community antenna processing system as a central operator unit or in a headend for the cable feed as a central control unit or as a repeater station for radio telephones is connected to the individual slave circuits 3 serving as channel strips via a bus system 5 , e.g. B. a bus line system 5 connected.

This bus system 5 comprises a selection or chain line 7 (daisy chain). Furthermore, at least one bidirectional or a first outward and a second inward-facing information bus or lines 9 for transmitting and / or receiving line is provided, which is connected via the master circuit to the n-connected slave circuits connected in series along the bus structure .

The embodiment of FIG. 1 includes the related to the master circuit, outward Sen deleitung 9 'and related to the master circuit 1 acting receiving line 9 ''. Each of the n provided slave circuits 3 - where n is an integer - each has a data connection D1 and D2, in this exemplary embodiment the data connection D1 in relation to the relevant slave circuit 3 as the output connection leading to the master-slave and the relate to connection D2 in relation to the master-slave serves as input connection D2 for receiving transmission signals.

In addition, each slave circuit 3 is connected via an input E and an output A to the aforementioned selection or chain line 7 .

As can be seen from the circuit diagram in FIG. 1 with the n slave circuits 3 shown there, a switch 13 is provided between the chain line input and the chain line output connection E, A of each slave circuit 3 in the chain line in exporting Fig. 1, for example approximately in accordance with a mechanical switch, which is automatically switched in for each one slave circuit in its open position. Removing or not occupying an intended connection or slot 15 by a slave circuit 3 automatically leads, such as in the vacant space 15 , that the chain line switch 13 provided in the chain here in its closed position for switching through the ket line is brought.

The structure is now such that the slave circuit 3 which is the most distant from the master circuit is the first slave circuit 3.1 . The last slave circuit n is immediately adjacent to the master circuit 3 , so that the output A of this last slave circuit 3. n is connected to the corresponding transmit input of the master circuit 1 .

The entire structure is such that the individual slave circuits 3 can preferably only be switched between the different switching states by switching from one control level to another, for example from "high" to "low" or vice versa, the different operating or Result in communication states.

The different possible circuit states of the individual slaves including the possible states Inputs and outputs are basically from the end of the Description attached table can be seen.

As already stated, the chain line on gangs- and the chain line output signal either the Assume state low or state high. This one gangs and output states or signals at the individual Subsequently, as in the table, slaves become short as a chain line input signal "0", for example for the state low or as a chain line input or Chain line output signal "1" for the high state referred to, the assignment z. B. also vice versa can.  

The signal is at the chain line input of a slave "0" and also the output at the chain line output signal or the output status "0", this applies fende Slave locked, so that even in the event of a relevant slave present this first has to be withheld once (so there is none Communication release before).

A chain line input state "0" and a chain line The output output state "1" is not permitted for all slaves and does not occur in the present embodiment.

Is at the chain line entrance E of a relevant Sla If there is an input signal "1", the be hitting slaves in a permissible communication state, where when the chain line output signal is at "0" is a control sequence accordingly over the chains circuit takes place. In the event that a If there is a signal "1" for slaves, this is the case slave in an address-reinforced permissible communication cat state.

Finally, execution is always located in the described example of circuitry of the Kettenleitungs- input E of the master circuit 1 remotest are the slaves, in the shown exemplary embodiment, the input of the slave 1 is always "high" or "1". An input signal "0" (low) cannot be present in this exemplary embodiment at the chain line input of the first slave.

After commissioning of the circuit arrangement shown in FIG. 1, all inputs and outputs of all slaves are at circuit level "1". If a slave, for example the slave n-3 shown in FIG. 1, reports that it wants to provide information, it constantly switches its output to the "0" state. This state is then present at the chain line input of the next slave n-2. The table shows that the input signal to "0" and the output signal to "1" (switching status B) are not permitted. This means nothing other than that the input level signal "0" at the slave concerned immediately causes its output to be switched from the "1" state to the "0" state. In other words, according to the table, the slave concerned is thereby switched to the blocked state A, in which there is no communication release. However, switching the output of a slave to the chain line output state "0" automatically means that this state is immediately at the input of the next slave and this is also switched to the locked state, in which its chain line input and its Chain line output is in state "0" (circuit state A according to the table).

After the last slave closest to the master has switched to "0" in its chain line output, an alarm handling command can be sent from master circuit 1 via the information line, ie information bus 9 'to all slaves, for example. This causes the most distant slave with the communication condition chain line inputs in state "1" and chain line outputs in state "0" is in the permissible alarm response mode and sends the alarm signal block to the master via line 9 ''. After complete delivery of the signal block, the chain line output is switched to the operating state "1".

As a result, the next slave 2 is switched to its permissible communication state by the input signal "1" at the chain line input (whereby state "0" is still present at the output), while all subsequent slaves are still blocked.

This means that all slaves can use the relevant slaves one after the other Signal information blocks to the master circuit if there are corresponding signals in the slaves.

Conversely, corresponding addressing can also be carried out according to this chain switching principle by issuing a global query command from master circuit 1 . All slaves are switched so that their chain line outputs are in the "0" state, whereby the subsequent chain line inputs of the subsequent slave are also switched to this operating state. The first slave is thus in operating state C (table) and all subsequent slaves are in blocked operating state A (table). If there is no specific addressing from the master circuit for the first slave 1 , it switches its chain line output back to the "1" state, which activates the next slave. The only slave-specific addressing in the global query command issued by the master circuit 1 can thus be read selectively and independently of the address in the individual slaves.

From the described process it appears that this Derailleur principle always only one specific Slave in an allowed communication state located, which is characterized in that only this relevant activated slave on its chain line Input "1" and at its chain line off gang has the state "0".

Let the circuit principles outlined above generalize as follows:

• - A signal on the chain line 7 is a control signal for switching a slave from its locked state (no communication release) to a permissible communication state (communication release), in the exemplary embodiment the slave being blocked when the chain line input and output signal level is at "0" and then there is a permissible communication release for the slave in question as part of the chain sequence control if its chain line input is at signal level "1" and its chain line output is at signal level "0";
• - Both in locked operating state A and in a permissible communication state C or D (according to Table) each slave can receive commands from the master gene;
• - the operating state locked (operating state A) as a permissible communication state (case C or D according to the table) can also be used via Commands issued by the master circuit for the slaves be solved;
• - Due to an internal condition, each slave can dated Operating or communication state D in the state C and vice versa (table), z. B. in the event of an alarm interrupt;
• - Each slave is required to set a "0" state his chain line entrance to his chain office forwarding output. That is, such Change of state of a slave in the chain speaking forwarding to the master;
• - a slave whose chain line input (and thus  also its chain line output) on the closed level "0", ie when communication is blocked Release according to operating state A in the table det, can not by itself in a permissible Switch communication status. This requires one Change of the input signal by the corresponding one Control via the chain line output of the front switched slaves;
• - reaches the operating state (communication release locked) according to operating mode "A" in the table Master circuit without being triggered by it the master circuit can be commanded initiate the slave for data communication, the on its chain line input state "1" and on its chain line output the signal level "0" Has. If this communication is ended, be hit slave at its chain exit again Signal state "1" to take on the next Slave is passed towards the master. Is in this chain, however, is a slave, which is also a Communication signal to be delivered to the master stops riding, the switching of the operation becomes stood "1" from its entrance to its exit initially interrupted and inhibited until its communication cation with the master. Only after its chain line output becomes "1" and thus the next slave in permitted communication switched. The master receives the corresponding ones Communication signals and blocks from the various slaves until it reaches its chain entrance from the chain line output of the last slave coming status signal "1" is reached.

So with this timing chain line, the following are Control procedures possible, which are explained in detail  become:

• - automatic addressing procedure
• - Global system queries using a single command
• - Notification procedure by means of a targeted query
• - Connection of the control chain line.

The possible control methods explained above are briefly described below.

1. Automatic addressing procedure

The automatic addressing process ensures that individual slave circuits 3 can be removed or added under operating conditions without a previous address setting being necessary on these slave circuits.

The following options are available:

• - Read all addresses even with double or multiple addressing;
• - rapid global re-addressing;
• - Readdressing for unknown addresses of the unit ten;
• - Readdressing with double or multiple addressing.

1.1 Address reading

A "Address reading" command issued by the master circuit 1 on its transmission line 9 'causes that after receiving and decoding by the slave units, each of them sets its control line outputs A in their "0" mode. After a conditionally necessary control time has elapsed, the first slave unit 3.1 , which has the state "1" at the input and the state "0" at the output, sends its address information via the reception line 9 '' to the master circuit. As stated above, all chain inputs and chain outputs of all subsequent slaves are at signal level 0 and are therefore blocked (operating mode A according to the table). After the end of information, the control or chain line output line A is switched over again accordingly, whereby the next slave is activated. Corresponding to the chain sequence control, it is thus ensured that only the slave circuit 3 sends address information which is in operating mode state C according to the table.

The transmitted address information is read sequentially by the master unit. The end of information reading can in principle also be recognized by monitoring the time. However, this is preferably done by monitoring the control input line of the last slave circuit 3 which was connected directly before the master.

1.2 Sequence of the global address setting

With global addressing, a global address is entered in all slave units 3 using a global command. This global address causes all slave units to set control output A to "0".

With a subsequent address write command, which is only executed by the slave circuit 3, which has the state "1" at the control line input and the state "0" at the control line output, the intended address is entered. The newly entered address causes the control line output A to assume the state "1". The next slave unit thus receives 3 different states. A subsequent address write command with a newly provided address can now readdress this slave circuit 3 .

This address write command 1 is repeated until all slave circuits 3 are re-addressed if necessary.

1.3 Sequence single addressing with the same addresses (Dop pel or multiple addressing)

As explained above under the point "address reading" determines which addresses are occupied twice or more are. An address letter is sent to these addresses commands - that is, in an address-selective manner - the global address as above under "Sequence of Global Address setting "described, entered. This process can repeated for further double or multiple addressing become. With such an address write command now, as described above, for example only the slave units possessing global addresses are redirected become. Guarantee the slave units not affected forwarding.

2. Global system queries using a single command

System queries are conceivable at

• - Status queries of the overall system;
• - configuration queries of the overall system;
• - other system diagnostics.

Using a corresponding system query command through all slave units the control output lines in switched to the "0" state.

After a conditionally necessary control time has elapsed, the first slave circuit 3 , which has the state "1" at its control line input E and the state "0" at the control line output A, sends its system information to the master circuit 1 and controls it after the end of information, its control line output A also in the state "1". This (since its input and its output are in state 1) makes this slave circuit inactive, but it activates the next slave circuit in the overall chain that now sends out its system information (because its input is in the State "1" and its output are in state "0"). Then his control or chain line output A is set to 1. This process is repeated until all slave circuits 3 have sent out their system information. The transmitted system information is read sequentially by the master unit. The end of the information reading can also be recognized here again via time monitoring, but preferably by monitoring the control input line of the master circuit 1 .

3. Notification procedure by means of a targeted query

If a "monitoring" system status is generated and globally set by a command in the slave circuits, the serial control line is used in the reporting procedure. One or more slave circuits 3 , which want to send a message to the master circuit 1 , put their control or chain line output A to the state "0". This change in state of the control line is via the continuous chain of the downstream slave circuits 3 by switching all of their chain line inputs E and outputs A referred to below as control line inputs E and chain line outputs A to the state "0" to the master Circuit 1 passed. This is registered by the master circuit, which responds or can respond by means of a corresponding system query, and the slave circuits 3 , which have a state 1 at control line input E and a state "0" at control line output A. to send their registration information. The message information has included the address of slave circuit 3 . After stopping the Meldeinfor mation, the relevant slave unit 3 switches its control line output A to the state "1" and thus releases the next slave unit, which contains a piece of message information, to send it out. Are connected between the next slave unit, which will send information other slave circuits 3, which want to send any information, the switching pulse from state 2 to state 1 in these respective SLAVE circuits 3 respectively from the input to which is Output passed to the next slave circuit 3 until it is the turn of the slave circuit 3 in question that is to be held ready for information to be sent out and its input is switched to state 1. This slave circuit 3 then outputs the corresponding information on the receiving line 9 '' to the master circuit 1 . This process is repeated until all messages are sent to the master circuit and the control input line of the master circuit 1 also returns to state 1.

With the system query command described above, the monitoring state is canceled and other messages that arise during the system query must be stored in the corresponding slave circuits 3 until a new monitoring state is released again.

4. Connection of the control chain line

The connection of the control chain line 7 by closing the switch 13 mentioned is required in the case when slots 15 remain empty in the operating case or a certain slave circuit 3 is removed due to faults. In this case, the simplest solution is manual switching. In contrast, ger is a possibility in which the switch closes automatically by means of a sensor contact when the slave circuit 3 is removed.

As shown in FIG. 2, instead of a switch equipped with a mechanical sensor and / or a mechanical switch, a resistor diode arrangement or - as shown in FIG. 3 - a gate arrangement can achieve the same effect. As a result, the state 1 is set via the resistance due to the lack of potential in the slave circuit 3 which has been removed.

Fig. 2 differs with respect to Fig. 1 in that the chain line is guided via a diode-resistor combination. Thus, the mechanical contact can be omitted and its function can be realized by the circuit arrangement mentioned. A signal state "low" or "0" at the chain line input of a slave 3 is immediately effective at the chain line output A via the diode 25 . At the same time, however, a slave with detected "low", ie signal state "0", can have its output A (which should be the open collector or open drain) at its chain line input E at "low", ie "0" , activate. The forward voltage of the diode 25 is not effective in this case, so it need not be considered in more detail for this case. If, on the other hand, a slave is removed, only the diode now takes over the "low" (ie "0") information, so that the signal level is raised by the forward voltage. Depending on the defined input threshold value of the master and the diode used, the number of slave units that are not plugged in is limited such that the sum of the forward voltage is less than the threshold value input voltage.

The disadvantages apparent from the principle according to FIG. 2 are avoided in the embodiment according to FIG. 3 in that the passive component diode is replaced by an active component, a double AND.

Based on the table are the different operating mode states for the different input and Output signal pedal described.

In deviation from this, circuit arrangements are also conceivable which block a slave when its input and Initial state is at "1" and that for communication is unlocked when its inputs and outputs are in the State "0". Beyond that is fundamental also a circuit possible that has a permissible loading has the drive state when the Input and output chain tension, i.e. H. that corresponds level signal, is the same, so that for example concerned slave with unequal input and output chain state is locked.

Claims (9)

1. Control circuit with a status evaluation for slave circuits ( 3 ) which work together with a master circuit ( 1 ), in particular for a central community antenna processing system, for head ends for the cable feed or for repeater stations for radio telephones with the following features:

• - The master circuit ( 1 ) is connected to the slave circuits ( 3 ) via a bus system ( 7 , 9 ),
• - The bus system ( 7 , 9 ) comprises at least one common bidirectional serving for the information transmission or at least one first transmitting bus directed outwards to the master circuit ( 1 ) and a second receiving bus ( 9 , leading to the master circuit ( 1 )) 9 ', 9 '') and one for the Se lesson of the individual slave circuits ( 3 ) serving and in the manner of a chain line ( 7 ) formed selection bus,
• - The individual slave circuits ( 3 ) are connected in series via the chain line ( 7 ), the chain line output (A) of a slave circuit ( 3 ) each having the chain line input (E) of a next slave. Circuit ( 3 ) is connected,

characterized by the following features

• - The master circuit ( 1 ) is connected to the end of the chain line device ( 7 ), so that the chain line output (A) of the last in the chain line ( 7 ) switched slave circuit ( 3 ) at the control line input of the Master circuit ( 1 ) is connected or connected.

2. Control circuit according to claim 1, characterized in that at the chain line input (E) of the master circuit ( 1 ) most distant first slave circuit ( 3 ) permanently only one of the otherwise at least two different, to the Chain line inputs and outputs (E, A) of the slave circuits ( 3 ) can be applied to signal states. 3. Control circuit according to claim 1 or 2, characterized in that the slave circuits ( 3 ) can assume two permissible communication states (C and D), which differ only in their different signal state at the chain line output, each slave due to an internal condition or on the basis of an external condition initiated by the master circuit ( 1 ) between the two operating or communication states (C and D) can be switched. 4. Control circuit according to one of claims 1 to 3, characterized in that the circuit is constructed in such a way that at least when one of the two signal states is present at the chain line input (E) of a slave ( 3 ) an automatic switching through of this on the chain line Input (E) of the signals present on the chain line output. 5. Control circuit according to claim 3 or 4, characterized in that an allowable communication release for a slave circuit ( 3 ), in particular for a query including address reading but also for an addressing method with respect to a single slave circuit ( 3 ) is only possible if one of the two status signals is present at the chain line input (E) and the other of the two status signals is present at the chain line output (A). 6. Control circuit according to one of claims 1 to 5, characterized in that a slave circuit ( 3 ) is constructed such that after completion of a communication and termination of a permissible communication state (C, D) a switchover of the state signal on the chain line - Output (A) takes place. 7. Control circuit according to one of claims 1 to 6, characterized in that the circuit is constructed such that an interrogation or transmission cycle of the master circuit ( 1 ) is ended when the master circuit ( 1 ) from the chain line -Output (A) of the last slave circuit ( 3 ) receives the status signal which corresponds to the chain line input (E) of the first slave circuit ( 3.1 ). 8. Control circuit according to claim 1, characterized in that each slot ( 15 ) of a slave circuit ( 3 ) in the chain line ( 7 ) is assigned a switch ( 13 ) such that when the slave circuit ( 3 ) is plugged in and switched on. the relevant switch path between the chain line input (E) and the chain line output (A) of the relevant slave circuit ( 3 ) is interrupted and closed when the slave circuit ( 3 ) is removed.