JPH0723431A - Terminal mis-connection preventive exchange - Google Patents

Abstract

PURPOSE:To prevent mis-connection by detecting a loop current and the presence of ping-pong transmission when a single telephone set (SLT) in mis-connection to an exclusive telephone set interface (exclusive TELi/f) is hooked off so as to make warning display. CONSTITUTION:When an SLT in mis-connection is hooked off, a DC loop is closed, a loop current flows and detected by a loop detection section 1 and an output LOOP is active and the possibility of flowing of an overcurrent is precluded in the DC loop closing of the SLT. On the other hand, since the SLT has no ping-pong transmission means, communication data does not reach a transmission section 4 and an output VD is inactive, Then a logic circuit 2 makes logic arithmetic operation so that an output TELTYPE is active when the LOOP is active and the VD is not active. When the control section 3 detects the active state, a central control section (CC) 13 writes a signal of a port 14 to set the level of the port to a predetermined level. Thus, a driver 15 is started and an alarm LED 16 is lighted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching device which accommodates a single telephone (hereinafter referred to as SLT) and a dedicated telephone (hereinafter referred to as dedicated TEL) as extension telephones in a mixed manner.
Regarding prevention of erroneous connection between T and exclusive TEL.

[0002]

2. Description of the Related Art Conventionally, in an exchange apparatus which accommodates an SLT and a dedicated TEL in a mixed manner as an extension telephone, an existing rosette can be used for the main unit (exchange) and each telephone, so that the same type 2 It is generally wired by a wire cable.

FIG. 7 is a wiring diagram of a general two-wire cable. The contacts of the plugs at both ends (so-called 6-2 type modular plugs) use the two central contacts.

FIG. 8 shows a dedicated TEL interface (i /
It is a circuit diagram which shows the detail of f). This exclusive TELi / f
Has a function of transmitting and receiving a digitized voice signal and a control signal, and a function of supplying power to a dedicated TEL.

Next, each part in the figure will be described. The control unit 3 sends control information (command) from the CC (central control unit) to the dedicated TEL and also performs control to notify the CC of the control information (event) from the dedicated TEL.
The command includes contents such as "turn on LED", "display number", and "set into speaker receiving state" for the dedicated TEL. In addition, at the event
Information on the pressed key of L is included.

The transmission unit 4 is provided with a voice signal, a control signal, and a dedicated TE.
It has a modulation / demodulation function for transmitting to L and a function for detecting transmission abnormality. The transformer 8 is for transmitting / receiving a signal to / from the transmission line 9, and the choke coil 6 is a TEL dedicated to the transmission line 9.
It is a coil for superimposing a power supply power supply to. The capacitor 7 is for blocking direct current, and the thermistor 12 is for overcurrent protection.

FIG. 9 is an explanatory diagram schematically showing a voice signal and a control signal on the transmission line 9.

The voice signal is transmitted by Bch having a bit rate of 64 kbit / s, and the control signal is 16
It is transmitted by Dch having a bit rate of kbit / s. There are two Bchs, which is so-called 2B + Dch transmission. As a result, the data communication signal can be transmitted at the same time as the voice signal.

Further, the signal from the exclusive TELI / f to the exclusive TEL and the signal from the exclusive TEL to the exclusive TELi / f are alternately sent to the transmission line 9. That is, it is a so-called ping-pong transmission system in which bidirectional signals are transmitted in a time division manner. With this method, full-duplex communication on a two-wire transmission line is realized.

The transmission unit 4 has a signal line VD (Valid Data) for detecting an abnormality in communication data transmission with the dedicated TEL 11.
There is a). When communication data does not reach the transmission unit 4 for a certain period due to an abnormality in the transmission line 9, the VD becomes active. The control unit 3 detects this and notifies the CC.

FIG. 10 shows the internal structure of an SLT, particularly a 601 type telephone (so-called black telephone), which includes a hook switch (HS) 13 and a relay contact (Di) for transmitting a dial pulse as a selection signal. 14, a call circuit 15 including a DC loop closing unit, a transmitter / receiver unit, etc., a short-circuit relay contact (Ds) 16 of the call circuit 15, and a 16 Hz ringing signal loop for ringing a bell 18 when an incoming call arrives. Capacitor (C) 17 of.

Each contact in the figure represents a state during dial pulse transmission, HS is an off-hook state, Di is a make state, and D is a D-state.
s is in a short circuit state. Since the DC loop closing part of the communication circuit 16 has an inductance, it adversely affects the dial pulse waveform. To prevent this, Ds is short-circuited during dial pulse transmission.

By the way, in this state, L1-HS-D
Since a loop of i-HS-L2 is generated and the contact resistance of each contact is a small value, a short-circuit state is almost generated between L1-L2. However, the subscriber line to which the SLT is connected has a maximum power supply current of 120 mA, so there is no problem even if a short circuit occurs.

[0014]

However, if a black telephone is mistakenly connected to the exclusive TELi / f shown in FIG. 8, a short circuit will occur between the two lines of the transmission line 9 during dial pulse transmission, resulting in an overcurrent. Flowing. And the thermistor 12 for protection
However, the operation of the thermistor 12 is to generate heat when a current flows, which increases the resistance value.
It takes time for the protective effect to work. Therefore, over a short period of time, an overcurrent may flow and the internal circuit of the black telephone may be burned out. As a countermeasure against this, it is conceivable to change the modular pin arrangement between the SLT and the dedicated TEL, but this makes it impossible to use a standard two-wire cable as shown in FIG.

The present invention is an SLT for exclusive TELi / f.
It is an object of the present invention to provide an exchange device capable of preventing erroneous connection of.

[0016]

The present invention is based on the exclusive TELi /
Loop current when off-hook of SLT which is wrongly connected to f,
The presence or absence of ping-pong transmission is detected, and a warning is displayed depending on the status of both.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a circuit diagram showing the structure of a switching device according to a first embodiment of the present invention. The same components as those of the conventional example will be described with the same reference numerals.

This switching device makes a logical decision between a loop current detection unit 1 for detecting a loop current supplied to a telephone, an output LOOP of the loop current detection unit 1 and an output VD of a transmission unit 4, and outputs its output TELTYPE. Is output to the control unit 3.

Further, this switching apparatus includes a time switch 12 for time-division switching and a CC for controlling each part of the switching apparatus.
13, a port 14 that becomes an I / O of the CC 13, and a driver 15 that lights the alarm LED 16.

Further, this switching device is a codec (CODEC) for converting PCM voice data into analog voice.
24, a speaker driving unit 25 including an amplifier and a transformer, a speaker 26 installed in a premises where the present switching device is installed, and PCM audio data converted into compressed data for storage in a memory and vice versa. An audio data conversion unit 27 that performs conversion, and an R that stores compressed audio data
An OM 28, a RAM 29 for storing compressed audio data,
It has a control unit 30 which controls the PCM voice data on the highway to be stored in the RAM 29 and the compressed voice data of the RAM 29 and the ROM 28 to be sent to the highway.

Further, the voice data conversion section 27 uses the signal line D
RAM29, ROM28 by MARQ and R / W
Request for direct memory access (DMA). ROM 28 or RAM 29 according to the R / W logic
It is recognized whether it is a read from or a write to the RAM 29, and the DMARQ is notified to the control unit 3 by the DMARQ according to the timing of each read / write.

The compressed audio data stored in the RAM 29 is retained by the backup circuit 31 such as a battery even when the power is cut off.

Further, in the illustrated example, the SLT 10 is erroneously connected to the dedicated TELi / f, and the dedicated TEL 11 is correctly connected.

The other parts are the same as the conventional ones, and the description thereof will be omitted.

FIG. 4 is a circuit diagram showing details of the loop current detector 1. The loop current detection unit 1 includes a photocoupler PC having a bidirectional input unit (light emitting unit) and a varistor V.
R and the current limiting resistor R1 of the light emitting portion of the photocoupler PC
And a collector resistance R2 of the light receiving portion. In this circuit, when a loop current flows, the voltage across the varistor VR is clamped at about 2V. Therefore, this voltage causes a current to flow in the LED of the light emitting portion of the photocoupler PC,
It is transmitted to the light receiving part.

Next, the operation of this embodiment will be described with reference to the flow charts of FIGS. FIG. 2 is a flowchart showing the operation of detecting an erroneous connection.

First, when the erroneously connected SLT goes off-hook, the DC loop is closed (S1). As a result, a loop current flows, the loop current is detected by the loop current detector 1, and the output LOOP becomes active (S2).

When the DC loop of the SLT is closed, the DC resistance value is 50 to 300Ω according to the regulations of the terminal equipment and the like, so that there is no risk of overcurrent. On the other hand, SLT
Since there is no ping-pong transmission means, the communication data does not reach the transmission unit 4, so the output VD becomes non-active (S3).

The logic circuit 2 outputs the signal TELT when LOOP is active and VD is non-active.
A logical operation is performed so that YPE becomes active. In this embodiment, the desired output is obtained by taking the logical product of the negative output of VD and LOOP.

In this way, TELTYPE becomes active (S4). The meanings of LOOP and VD in other states are as follows.

First, LOOP is inactive and VD
Is inactive, none of the telephones is connected or the SLT is connected, but is in the on-hook state.

LOOP is non-active and VD
If is active, neither phone is connected,
It is meaningless because the communication data exists while the SLT is on-hook.

Further, when LOOP is active and VD is active, a dedicated TEL is connected.

The dedicated TEL is MPU, CODEC-IC,
Since it has a speaker, LED, etc.
It consumes a current of 0 to 30 mA. Therefore, the output of the loop current detector 1 becomes active. Therefore, the VD determines whether the SLT is in the off-hook state or the dedicated TEL.

Next, FIG. 3 is a flow chart showing the operation of issuing a warning.

First, the control section 3 monitors the TELTYPE (S5). Then, when detecting the active, the control unit 3 notifies the CC 13 to that effect, and the CC 13
Writes port 14 and sets it to a predetermined value (S
6). As a result, the driver 15 is activated and the alarm LED 16 is turned on (S7).

As described above, when an erroneous connection is detected, the alarm LED is turned on and a visual warning is issued.

Next, FIG. 5 is a block diagram showing a second embodiment of means for issuing a warning.

In the figure, the oscillator circuit 17 is activated by the port 14 and generates an AC signal for driving the sounder 18.

FIG. 6 is a flow chart showing an operation for issuing a warning with such a configuration.

First, the control section 3 monitors TELTYPE (S8). And when it detects activity,
The CC 13 writes the port 14 and sets it to a predetermined value (S9). This activates the oscillator circuit 17,
The oscillation operation is started (S10). The sounder causes the sounder 18 to ring (S11).

As described above, when the incorrect connection is detected, the sounder 18 sounds and an audible warning can be issued.

Next, a third embodiment of the present invention will be described. In the third embodiment, when a wrong connection of the SLT is detected, a voice message is sent by a local broadcast to issue a warning.

The configuration of the entire apparatus and the configuration of the loop current detector 1 are assumed to be the same as in the first embodiment (FIGS. 1 and 4). The operation of detecting an erroneous connection is also the same as that of the first embodiment (FIG. 2), and the description thereof will be omitted.

Next, FIG. 11 is a flow chart showing the operation at the time of reproducing the audio data in the third embodiment.

First, the control section 3 monitors the TELTYPE (S15). Then, when detecting the active state, the control unit 3 notifies the CC 13 to that effect, and in response to this, the CC 13 notifies the control unit 30 of the audio transmission unit including the audio data conversion unit 27 to the backup circuit 31 (S16). ). At the same time, the process moves to the local broadcast process, which will be described later.

By the way, in a voice data compression method such as ADPCM, PCM data of 64 Kbps is generally converted into compressed data of 32 Kbps. Therefore,
When the control unit 30 designates R / W as read, the audio data conversion unit 27 outputs 8 K every 32 Kbps, that is, 250 μs.
The DMARQ is set so as to store the bit data, and the DMA request is issued to the control unit 30 (S17).

In response to this request, the control unit 30 causes the ROM 2
The compressed audio data is read out from S8 (S18) and stored in the audio data converter 27 (S19). After that, the voice data converter 27 resets the DMARQ (S2
0), the compressed voice data is converted into PCM voice data (S21). The audio data converted into PCM is sent to the highway at 64 Kbps (S22).

FIG. 12 is a flow chart showing the operation of the local broadcast.

First, after TELTYPE becomes active, the CC 13 controls the time switch 12 to connect the private broadcast i / f composed of the codec 24 to the speaker 26 to the audio transmission section (S23).

Then, the PCM voice data is converted into the codec 2
4 (S24) and converted to analog voice (S)
25). The analog voice is amplified by the speaker drive unit 25 (S26) and output from the externally connected speaker (S27). A warning message is stored in the ROM 28, and, for example, a warning "The phone type is different." Is issued from the speaker 26.

As described above, when an erroneous connection is detected, a warning message is issued by the local broadcast.

In the third embodiment described above, the warning message fixedly stored in the ROM is used, but it is also possible to record an arbitrary message in the RAM and issue it by the local broadcast.

FIG. 13 is a flowchart showing the recording operation of voice data.

First, when the key operation corresponding to message recording is performed in the dedicated TEL 11 (S28), CC
13 is a dedicated TELi / f in which the dedicated TEL 11 is accommodated.
And the audio sending unit are connected (S29). And TE
A message to be recorded is input from L11 (S30).
This message input is performed in the same manner as in normal speech transmission.

Then, the voice of this message is
It is converted into PCM inside L11 and input to the audio data conversion unit 27 of the audio transmission unit via the dedicated TELi / f and the time switch 12 (S31). Here, the PCM audio data is converted into compressed data of 32 Kbps (S32).

Further, the key operation of the exclusive TEL 11 is CC.
13 notifies the control unit 30 of the audio transmission unit. When the control unit 30 designates R / W as light, the audio data conversion unit 27 causes the audio data conversion unit 27 to output 8 bits every 32 Kbps, that is, 250 μs.
The compressed audio data of No. 1 is output to the data bus, DMARQ is set, and a DMA request is made to the control unit 30 (S3).
3).

In response to this request, the control unit 30 causes the RAM 2
The compressed audio data is written in 9 (S34). After that, the voice data converter 27 resets the DMARQ (S3
5) The output of the compressed audio data of the next frame is on standby.

Next, FIG. 14 is a flow chart showing the reproducing operation of the audio data.

The control section 3 monitors TELTYPE (S36). Then, when the active is detected, the control unit 3 notifies the CC 13 to that effect, and in response to this, the CC
13 notifies the control unit 30 of the audio transmission unit (S3).
7).

At the same time, the process shifts to the local broadcast process. When the control unit 30 designates R / W as read, the audio data conversion unit 27 causes the audio data conversion unit 27 to output 8 bits every 32 Kbps, that is, 250 μs.
The DMARQ is set so as to store, and a DMA request is made to the control unit 30 (S38).

In response to this request, the control unit 30 causes the RAM 2
The compressed audio data is read out from S9 (S39) and stored in the audio data converter 27 (S40). After that, the voice data converter 27 resets the DMARQ (S4
1), the compressed voice data is converted into PCM voice data (S42).

The voice data converted into PCM is sent to the highway at 64 Kbps (S43). Subsequent in-house broadcasting processing is the same as in the third embodiment described above.

As described above, the arbitrarily recorded warning message is issued by the local broadcast.

Next, a fifth embodiment of the present invention will be described. In the fifth embodiment, when the erroneous connection of the SLT is detected, the power supply to the exclusive TELi / f is stopped.

The configuration of the entire apparatus and the configuration of the loop current detector 1 are the same as those of the first embodiment (FIGS. 1 and 4). The operation of detecting an erroneous connection is also the same as that of the first embodiment (FIG. 2), and the description thereof will be omitted.

FIG. 15 is a block diagram showing the exclusive T in the fifth embodiment.
It is a flow chart which shows operation which stops electric power feeding to ELi / f.

First, the control section 3 monitors TELTYPE (S45). Then, when the active state is detected, the control unit 3 controls the power feeding circuit 5 to stop its operation (S6).

FIG. 16 is a circuit diagram showing the details of the power supply circuit 5, where rl is a contact of the relay RL, TR is a transistor for relay drive, D is a diode for absorbing back electromotive force in the winding portion of the relay RL, R1 and R2 are transistors TR
This is a resistor for supplying the base voltage of.

Normally, the output of the control unit 3 is "H",
Since the base voltage is applied, the transistor TR is turned on.
Therefore, the winding portion of the relay RL is energized. Therefore, the contact rl is turned on and the power is supplied.

When TELTYPE active is detected, the output of the control unit 3 becomes "L" and the base voltage disappears, so that the transistor TR is turned off.
The energization of the winding part of the relay RL is stopped. Therefore, contact point r
l turns off and power supply stops.

As described above, when the incorrect connection is detected, the exclusive TELi / f power supply circuit 5 is stopped and the incorrect connection S is made.
Prevents overcurrent from flowing into the LT.

In the fifth embodiment described above, the power supply is turned ON / OFF by using the relay, but an element whose resistance value changes with voltage, for example, a MOS-F as shown in FIG.
The same effect can be realized by using ET.

That is, in FIG. 17, the output voltage of the control unit 3 applied to the gate G changes the drain D-source S.
The resistance value between is converted. Therefore, the MOS-FET may be selected so that the resistance value becomes substantially 0 when TELTYPE is inactive, and the resistance value becomes high when TELTYPE is active, and the power supply is substantially stopped.

Next, a seventh embodiment of the present invention will be described. In the seventh embodiment, when an erroneous SLT connection is detected, a warning sound is generated from the dedicated TEL.

The configuration of the entire apparatus and the configuration of the loop current detector 1 are assumed to be the same as in the first embodiment (FIGS. 1 and 4). The operation of detecting an erroneous connection is also the same as that of the first embodiment (FIG. 2), and the description thereof will be omitted.

FIG. 18 is a flow chart showing the operation when the warning sound is emitted from the exclusive TEL.

First, the control section 3 monitors TELTYPE (S55). Then, when detecting the active, the control unit 3 notifies the CC 13 to that effect. afterwards,
The CC 13 controls the time switch 12 to normally operate the dedicated switch.
A warning sound is sent to the exclusive TELi / f highway to which the EL is connected (S56).

The warning sound is prepared as PCM tone data in the time switch 12, like the dial tone and busy tone.

The warning sound sent to the highway is
It is transmitted from Li / f to the dedicated TEL, the analog warning sound is converted inside, and sounds from the built-in speaker (S5).
7).

As described above, when an erroneous connection is detected, a warning sound is emitted from the properly connected exclusive TEL.

In the seventh embodiment described above, the warning sound is emitted from the dedicated TEL, but the same effect can be obtained by issuing a warning message by voice.
Similar to the above-mentioned PCM tone data, this is because the warning message is stored in the memory in the form of digital data, and the exclusive TELi / f is controlled by the control of the time switch 12.
To the highway. For example, a message such as "The phone type is different" is issued from the dedicated TEL. As described above, since the warning is a voice message, it is easier to recognize.

Further, the liquid crystal or the like of the exclusive TEL may be used to display a warning on the display or to turn on the LED, and these displays may be used together with the warning sound and the message.

In each of the above embodiments, the fact is detected by the off-hook of the SLT that is erroneously connected. However, in the on-hook state, as is clear from FIG.
Since the hook switch HS is in the open state, no current flows and there is no problem.

[0085]

As described above, according to the present invention,
Even if the SLT is mistakenly connected to the dedicated TELi / f, it gives a visual or audible warning when off-hook,
There is an effect that the erroneous connection can be promoted and the inflow of the overcurrent due to the erroneous connection can be prevented.

Further, as a result, the standard pin arrangement of 2 W
The modular code can be used for exclusive use of TEL, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an overall configuration in a first embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of detecting an erroneous connection of a telephone in the first embodiment.

FIG. 3 is a flowchart showing an operation of issuing a warning in the first embodiment.

FIG. 4 is a circuit diagram showing details of a loop current detector of the first embodiment.

FIG. 5 is a block diagram showing a means for issuing a warning in the second embodiment of the present invention.

FIG. 6 is a flowchart showing an operation of issuing a warning in the second embodiment.

FIG. 7 is a wiring diagram of a general two-wire cable.

FIG. 8 is a circuit diagram showing details of a dedicated TELi / f.

FIG. 9 is an explanatory diagram schematically showing audio signals and control signals on a transmission path.

FIG. 10 is a circuit diagram showing an internal configuration example of an SLT.

FIG. 11 is a flowchart showing an operation at the time of reproducing audio data according to the third embodiment of the present invention.

FIG. 12 is a flow chart showing an operation of a local broadcast in the third embodiment.

FIG. 13 is a flowchart showing a voice data recording operation in the fourth embodiment of the present invention.

FIG. 14 is a flowchart showing an audio data reproducing operation in the fourth embodiment.

FIG. 15 shows the exclusive TELi / in the fifth embodiment of the present invention.
It is a flow chart which shows operation which stops electric power feeding to f.

FIG. 16 is a circuit diagram showing details of a power supply circuit in the fifth embodiment.

FIG. 17 is a circuit diagram showing details of a power supply circuit according to a sixth embodiment of the present invention.

FIG. 18 is a flow chart showing an operation when a warning sound is emitted from a dedicated TEL in the seventh embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Loop current detection part, 2 ... Logic circuit, 3, 30 ... Control part, 4 ... Transmission part, 5 ... Power supply circuit, 12 ... Time switch, 13 ... CC, 14 ... Port, 15 ... Driver, 16 ... Alarm LED , 24 ... Codec, 25 ... Speaker drive section, 26 ... Speaker, 27 ... Audio data conversion section, 28 ... ROM, 29 ... RAM, 31 ... Backup circuit.

Claims (6)

[Claims] 1. In a switching device which accommodates a single telephone and a dedicated telephone in an extension, a connection detection means for detecting that the single telephone is connected to a dedicated telephone interface, an alarm display means for displaying an alarm, and the connection detection. And a control means for displaying an alarm in accordance with the detection result of the means. 2. An exchange apparatus for accommodating a single telephone and a dedicated telephone in an extension, a connection detecting means for detecting that the single telephone is connected to a dedicated telephone interface, a private broadcasting means for broadcasting a broadcast on the premises, and a voice message. Terminal misconnection preventive exchange device, comprising: a voice message sending means for sending a message to the private broadcasting means; and a control means for issuing a warning message from the private broadcasting means according to the detection result of the connection detecting means. . 3. The terminal erroneous connection prevention exchange device according to claim 2, wherein the warning message sent by the voice message sending means can be arbitrarily registered. 4. An exchange apparatus for accommodating a single telephone and a dedicated telephone in an extension, a connection detecting means for detecting that a single telephone is connected to a dedicated telephone interface, and the exclusive use according to the detection result of the connection detecting means. A terminal erroneous connection prevention / exchange device, comprising: a control means for stopping a power supply circuit of a telephone. 5. An exchange apparatus for accommodating a single telephone and a dedicated telephone in an extension, a connection detecting means for detecting that a single telephone is connected to a dedicated telephone interface, and the exclusive use in accordance with a detection result of the connection detecting means. A terminal erroneous connection prevention exchange device, comprising: a control unit for issuing a warning from a telephone. 6. The connection detection unit according to claim 1, wherein the connection detection unit detects a loop current, a detection unit that detects a communication state of the dedicated telephone, and outputs of both of them. A terminal erroneous connection prevention exchange device, comprising: a determination unit that performs a logical determination.