JPH0552107B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a PCM bus fault detection method in a PBX.

<Prior Art> Conventionally, there are the following methods for detecting a PCM bus failure in a PBX. This method sets PCM data for fault detection in the PCM data conversion memory of the common control card, and
The PCM data is sent from the common control card to the peripheral trunk card using a free line on the PCM bus.
After the PCM data received by the peripheral trunk card is taken into the time division bus control circuit provided in the peripheral trunk card, a coder/decoder (CODEC) provided in the peripheral trunk card is sent. Enter. The CODEC has a PCM data loopback function, and the PCM data input to the CODEC is looped back from the peripheral trunk card to the common control card using the free line of the PCM bus. Then, compare the PCM data looped back to the common control card with the PCM data set in the PCM data conversion memory.
It was designed to detect PCM bus failures.

<Problems to be solved by the invention> However, the PCM in the above conventional PBX
In the bus failure detection method, the CODEC installed in the peripheral trunk card is provided with a PCM data loopback function, and the PCM data is looped back via the time-sharing bus control circuit installed in the peripheral trunk card. Therefore, if a problem occurs due to a failure in the CODEC, it is difficult to determine whether the problem is due to a failure in the CODEC or the time-sharing bus control, and it takes time to recover from the failure. There is a problem that it takes. Furthermore, since the above CODEC has a loopback function, there is a problem that it is expensive.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for detecting a PBX bus failure in a PBX that performs loopback using an inexpensive circuit in which the CODEC does not have a loopback function and has a short failure recovery time.

<Means for Solving the Problems> In order to achieve the above object, the present invention converts audio signals from a PCM bus capable of transmitting data and a telephone line into PCM data using a CODEC, and converts this PCM data into PCM data. a peripheral trunk card that outputs the above PCM bus at a predetermined timing through a time-sharing bus control circuit;
It is equipped with a common control card that exchanges the PCM data with the peripheral trunk card via a PCM bus, and sets PCM data for fault detection in the PCM data conversion memory of the common control card, and also sets the PCM data for fault detection in the PCM data conversion memory of the common control card. The above PCM data is sent from the card to the above peripheral trunk card using the free line of the above PCM bus, and the PCM data for failure detection is looped back from the above peripheral trunk card to the above common control card, and the above PCM In the PCM bus failure detection method in a PBX, which detects a failure in the PCM bus by comparing the PCM data set in the data conversion memory with the PCM data looped back from the peripheral trunk card to the common control card, A shift register is provided in the time-sharing bus control circuit of the peripheral trunk card, and after storing the PCM data sent from the common control card in this shift register, this PCM data is transferred from the peripheral trunk card to the PCM. It is characterized by looping back to the control card mentioned above while taking advantage of available bus lines to detect PCM bus failures.

<Function> The common control card is for fault detection.
The PCM data is set in the PCM data conversion memory, and the PCM data is transmitted to the peripheral trunk card using a free line of the PCM bus. The peripheral trunk cards listed above are listed above.
After storing the PCM data in the shift register provided in the time-sharing bus control circuit, this
The PCM data is looped back to the common control card while timing is taken using the free line of the PCM bus. The above common control card transfers the PCM data looped back from the above peripheral trunk card to the above PCM.
A fault in the PCM bus is detected by comparing it with the PCM data set in the data conversion memory.

<Examples> The present invention will be described in detail below with reference to illustrated examples.

In FIG. 1, 1 is a common control card (hereinafter referred to as CCC), 2 is a peripheral trunk card (hereinafter referred to as PTC), 3 is a time division bus, and 4 is a message bus. The above CCC1 is
Responsible for the overall control and switching functions of the PBX (switching equipment),
PTC2 provides an interface between multiple telephone lines and the interior of the switch. Time division bus 3
In this example, is a data bus consisting of 8-bit parallel signal lines, and transmits PCM data between the CCC1 and the PTC2. The message bus 4 transmits messages (on/off hook detection signals, dial pulse control signals, etc.) for data control between the CCC 1 and the PTC 2. Although not shown, the time division bus 3 and message bus 4 have the same functions as the PTC 2.
Multiple PTCs are connected. For example, one PBX system can be configured with multiple 8-line PTCs and one CCC.

The CCC 1 is the master of the time division bus 3 and message bus 4, and controls all PTCs. This control is carried out by the main CPU 11, based on the station data program 12, and the time division bus control circuit 13 and the message bus.
This is done by controlling the CPU 14. The time-division bus control circuit 13 takes in the PCM data sent from the PTC 2 via the bus buffer 16 and internal bus 17 into the PCM data conversion memory 18 provided in the time-division bus control circuit 13. At the timing of the time slot, the data is transferred from the PCM data conversion memory 18 to the internal bus 19 and the bus buffer 20.
It outputs to the time division bus 3 via. Further, the message bus CPU 14 reads a message for data control from the ROM 21 and outputs it to the message bus 4, while the PTC 2 receives the message, takes in the message output from the message bus 4, and stores it in the RAM 22.

The PTC 2 converts the audio taken in from the line circuits 25, 25 into PCM data using the CODECs 26, 26. The PCM data passes through the time division bus control circuit 28, is converted into parallel data by the serial/parallel conversion circuit 29, and is transmitted through the internal bus 30 at the time slot timing determined by the time division bus control circuit 28. The signal is output from the bus buffer 31 to the time division bus 3. On the other hand, the above PTC2 is
The PCM data that the CCC 1 outputs to the time division bus 3 at the timing of the time slot of the other party is taken in at the above timing, and is sent to the parallel/serial conversion circuit 3 via the bus buffer 33 and internal bus 34.
Enter 5. The parallel/serial conversion circuit 35 converts the PCM data into serial data, and the CODECs 26 and 26 convert the data into audio signals, which are output from the line circuits 25 and 25. Further, the card CPU 37 takes in the message that the message bus CPU 14 outputs to the message bus 4, and transfers the message to the RAM 3.
8, while outputting the message read from the ROM 39 to the message bus 4.

When detecting a fault in the PCM bus (time division bus or internal bus) using the CCC1 above, use the CCC1 above.
This is done by looping back the PCM data between PTC1 and PTC2. The above CCC1 is PCM
When there is an empty line on the bus, a maintenance program is run periodically, and based on this program, the main CPU 11 sends a message to the message bus CPU 14 to the PTC 2 to perform loopback using the empty line. Instruct them to do so.

Upon receiving the message from the message bus CPU 14, the card CPU 37 confirms that the vacant line is not in a call state, and the time-sharing bus control circuit 28 operates at the timing of the vacant line.
The time division bus control circuit 28 is set so that PCM data can be stored in the shift register 40 provided in the time division bus control circuit 28. The time division bus control circuit 28 does not need to input the PCM data to the CODEC 26 as in the conventional example, and instead loops back the PCM data stored in the shift register 40 without providing the CODEC 26 with a loop back function. There is. Above time division bus control circuit 2
When the setting of 8 is completed, the above card CPU 37
Sends a message to CCC1 that loopback can be performed. Upon receiving this message, CCC1
Loopback data is set in the PCM data conversion memory 18 at the timing of the empty line.
This set PCM data is outputted to the time division bus 3 by the time division bus control circuit 13 at the timing of the timing slot of the vacant line.

The PTC 2 takes in the PCM output from the time division bus 3 at the same timing as the above timing, converts it into serial data in the parallel/serial conversion circuit 35, and stores it in the shift register 40. This stored PCM data is converted into parallel data by the serial/parallel conversion circuit 29, and is output to the time division bus 3 at the timing of transmitting the PCM data to the CCC 1 using the above-mentioned empty line.

CCC1 is the above looped back from PTC2
Import PCM data from time-sharing bus 3 and use the above
A fault in the PCM bus is detected by comparing it with the PCM data set in the PCM data conversion memory 18. If the above two PCM data match, it is assumed that there is no failure and the loopback is completed.

Next, upon completion of the loop back, the message bus CPU 14 notifies the card CPU 37 via the message bus 4 that the loop back using the empty line is to be completed. Card CPU3
In response to this notification, CCC 7 unsets the loopback of the time division bus control circuit 28 to restore the line, notifies CCC 1 through the message bus 4 that the loopback has been turned off, and completes the series of operations.

On the other hand, the above CCC1 receives the PCM data looped back from PTC2 and the PCM data conversion memory 1.
If it is determined that the PCM data set to 8 do not match, it is determined that there is a failure. In this case, all you need to do is verify the route from CCC1 to the PTC2 time division bus control circuit.
Since it is not necessary to verify the CODECs 26 and 26, failure recovery can be performed in a correspondingly shorter amount of time.

<Effects of the Invention> As is clear from the above, the PCM bus failure detection method in a PBX of the present invention provides a shift register in the time-sharing bus control circuit provided in the peripheral trunk card, and connects the common control card to the shift register. After storing the PCM data for fault detection sent from
Since this PCM data is looped back to the common control card using the PCM bus to detect a PCM bus failure, a simple and inexpensive circuit that does not have a loopback function in the CODEC and only has the above shift register is installed. can detect PCM bus failures. In addition, when a fault is detected, it is only necessary to verify the route from the common control card to the time-sharing bus control circuit of the peripheral trunk card, and there is no need to verify the CODEC, so it takes less time to recover from the fault. can be done.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the circuit configuration in one embodiment of the present invention. 1... Common control card, 2... Peripheral trunk card, 3... Time division bus, 2
8...Time division bus control circuit, 40...Shift register.

Claims (1)

[Claims] 1. A PCM bus capable of transmitting data and voice signals from a telephone line are converted into PCM data by a CODEC, and this PCM data is transmitted to the above at a predetermined timing through a time-sharing bus control circuit.
It is equipped with a peripheral trunk card that outputs to the PCM bus, and a common control card that sends and receives the PCM data to and from the peripheral trunk card via the PCM bus, and transmits the PCM data for failure detection to the common control card. In addition to setting it in the PCM data conversion memory of
Send the PCM data from the common control card to the peripheral trunk card using the vacant line of the PCM bus, and loop back the PCM data for failure detection from the peripheral trunk card to the common control card. The above PCM data set in the above PCM data conversion memory is compared with the PCM data looped back from the above peripheral trunk card to the common control card.
In a PCM bus fault detection method in a PBX that detects a PCM bus fault, a shift register is provided in the time-sharing bus control circuit of the peripheral trunk card,
After storing the PCM data sent from the common control card in this shift register, this PCM data is looped back from the peripheral trunk card to the control card using the free line of the PCM bus at the appropriate timing. A method for detecting a PCM bus failure in a PBX, the method comprising: detecting a PCM bus failure.