JPH0440196A - Controller for subscriber circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a subscriber circuit control device, and is particularly useful when a brightness control signal sent from a telephone digital exchange to a subscriber circuit is erroneous. It is.

<Prior art> The subscriber circuit connected to the telephone digital exchange is BOR.
It has various functions collectively referred to as 3CRT. Among these, B means call current supply, O means overvoltage protection, R means calling signal sending, S means monitoring, C means code decoding, H means 2-wire 4-wire signal conversion, and T means testing. .

A subscriber circuit according to this prior art is shown in FIG. In the figure, 1 is a telephone, 2 is an arrester with a 0 function, 3 is an R7 function section, 4 is a BSH function section, 5 is an encoding/decoding section (A/D and D/A conversion section), and 6 is a control section. be. Of these, the R7 function section, the BSH function function, and the 4 control section 6 are each formed by one LST.

In such a subscriber circuit, the control unit 6 interprets and processes the control signal from the PCM highway 7 and sends it to the RT function unit 3 and the BS.
It controls the H function function and 4 encoding/decoding unit 5, respectively, and multiplexes the subscriber line status signals of the RT function unit 3 and BSH function function 4 with the PCM encoded audio signal from the encoding/decoding unit 5. and sends it to PCM Highway 7.

An example of a more detailed block diagram of the control section 6 is shown in FIG. As shown in the figure, this control section 6 includes a serial-to-parallel conversion circuit that combines shift registers 8m and 8b and latch registers 9a and 9b, a control data check circuit 10, a timing generation circuit 11, and a signal multiplexing circuit 12. have.

Among these, the serial/parallel conversion circuit converts control signal data inputted in 8-bit burst serial format into serial/parallel data.

The control data check circuit 10 prevents the normal switch and lever switch of the RT function section 3 from being turned on simultaneously, and
In order to prevent collision between the calling signal sent from the functional unit 3 and the communication current from the BSH functional unit, exclusive logic is established and checked between each control data.

The timing generation circuit 11 is basically configured with a synchronous counter to ensure high-speed logic operation, and sends a shift clock to the serial/parallel conversion circuit, a strobe signal for latching, and a multiplexed timing signal to the signal multiplexing circuit 12. It is supposed to be done. Each of these signals is generated by a counter that counts a 2.048 MHz clock, and the initial reset of the counter is performed by a synchronization signal that arrives at a cycle of 8I&. Therefore, if an erroneous synchronization signal such as external noise is input, each of the signals of the timing generation circuit 11 will be generated at the erroneous timing and will take in the erroneous control signal on the PCM highway 7. (The timing generation circuit 11 is configured so that an initial reset is not applied even if a synchronization signal is input until the contents of the counter reach a set value. In this way, the synchronization signal is Since the control signal is not taken in even after the delay, the latch registers 9m and 9b hold their outputs as they are, so the state of the subscriber circuit is not disturbed.

The signal multiplexing circuit 12 combines the 8-bit PCM audio signal from the encoder/decoder 5 with the BSH function and the telephone 1 that outputs the BSH function.
On-hook, off-hook state signals, dial pulse signals, and ring trip state signals detected by the ring trip circuit are multiplexed onto a predetermined time slot on the PCM highway 7 and transmitted.

<Problems to be Solved by the Invention> As described above, the control section 6 has a timing generating circuit 11.
The initial reset of the counter will not be applied even if a synchronization signal is input until the contents of the counter reach the set value.
Therefore, the subscriber circuit according to the prior art having this control unit 6 is configured so that when the synchronization signal is erroneous or interrupted, the latch registers 9a and 9b hold the value just before the synchronization signal. There is. As a result, even if the synchronization signal is interrupted for a long time, the state immediately before the interruption will continue to be maintained.

Therefore, for example, if the synchronization signal is interrupted when a calling signal is being sent out, the calling signal will have to be sent out in a controlled manner, resulting in the following problems.

- For telephone subscribers, abnormal operations occur, such as the telephone's bell ringing continuously and the ringing tone continuing to be heard from the handset even when the handset is off-hook.

■ For the telephone exchange, even if the telephone subscriber goes off-hook, it continues to send out a high-power ringing signal, resulting in wasted power.

In view of the problems of the prior art described above, the present invention provides a control device for a subscriber circuit that can control the functions of each part to a desired state, such as turning off the functions of each part when the synchronization signal is interrupted for a long time. The purpose is to

Means for Solving the Problems> The configuration of the present invention that achieves the above object takes in a control signal supplied via the PCM highway based on a synchronization signal and performs processing such as sending out a ringing signal and supplying talk current to the telephone. In a subscriber circuit control device that controls various functional units to be executed and also latches the control state immediately before the synchronization signal is interrupted when the synchronization signal is interrupted, the synchronization signal is used as a reset signal for a set time. a timer means that sends out a selection signal after the elapsed time; and a timer means that normally sends control data based on the control signal to each functional unit, and fixed data that is control data including predetermined control contents upon input of the selection signal. The apparatus is characterized in that it has an output section configured to send output to each functional section.

<Function> According to the present invention having the above configuration, when the synchronization signal is interrupted and the time during which the synchronization signal is interrupted exceeds the set time of the timer means, each part of the subscriber circuit receives a control signal instead of the control signal. Fixed data is supplied. As a result, the fixed data controls the functions of each part to a desired state, such as turning off the functions.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings. Note that parts that are the same as those in the prior art are given the same numbers, and redundant explanations will be omitted.

FIG. 1 is a block diagram showing a first embodiment of the present invention. As shown in the figure, the control unit 13 according to the present embodiment is
In addition to the conventional control unit 6, a timer 14 and an output unit 15 are provided.
have. The timer 14 uses the synchronization signal as the reset signal S.
The selection signal S2 is input when the set time or more has elapsed after the reset. This timer 14
The setting time should be set longer than the period of the synchronization signal. The output section 15 selects either the control data or fixed data that is the output signal of the control section 6 and supplies it to each functional section 3.4 and the encoding/decoding section 5 (see FIG. 6). be. At this time, the selection of control data and fixed data is switched depending on whether or not a selection signal S is supplied. That is, the selection signal S
When supplied, fixed data is selected; otherwise, control data is selected. The fixed data includes, for example, a pattern for turning off the functions 3 and 4.

According to this embodiment, each part of the subscriber circuit operates as follows.

(al) When the synchronization signal is normal, each part is controlled by the control data which is the output signal of the control part 6. That is, the selection signal S2 is not sent out from the timer 14.

('b) If the synchronization signal is interrupted and (timer setting time)>(time when the synchronization signal is interrupted)>(period of the synchronization signal), the selection signal S2 is not sent from the timer 14, and the PC
Since the acquisition of the control signal from the M highway 7 (see FIG. 6) is also interrupted, the value immediately before the synchronization signal is interrupted is output from the control section 6 as control data via the output section 15.

(If the C1 synchronization signal is interrupted and (time when the synchronization signal is interrupted)≧(timer setting time), the selection signal S is sent from the timer 14, and fixed data is output from the output unit 15. Since the fixed data turns off the functions of each functional section 3 and 4, it is possible to eliminate, for example, continuous transmission of a calling signal and wasteful consumption of power.

Note that the set time of the timer 14 is set to be longer than the expected synchronization signal error time (.

As a result, when the synchronization signal is temporarily erroneous, the state immediately before the error is maintained, and when the synchronization signal is interrupted for a long time, for example, each functional section 3, 4 is turned off. can be operated.

FIG. 2 is a block diagram showing a second embodiment of the invention. As shown in the figure, in this embodiment, the timer 16 is formed by a retriggerable monostable circuit 17, and the output section 18 is formed by a data selector 18a and a fixed data holding section 18.
b, 18c.

In this embodiment, the set time of the timer 16 is set by the values of the resistor R and capacitor C connected to the monostable circuit 17, but the other operations are exactly the same as in the first embodiment.

FIG. 3 is a block diagram showing a third embodiment of the present invention. As shown in the figure, this embodiment includes shift registers 8a, 8b, latch registers 9a, 9b, and control data check circuit 1 of the control section 6 whose functions can be easily converted into software.
0, the timer 14, and the data selector 18 of the output section 18
a and fixed data holding section 18b.

18c is formed by one microprocessor 19.

The subscriber circuits according to the first to third embodiments described above are more effective when used in a system in which a subscriber circuit 20 as shown in FIGS. 4 and 5 is extended using a digital transmission path 21, for example. be. In this system, digital transmission line 2
1 goes outside the telephone station I, so there is a high probability that the digital transmission line 21 will be disconnected due to a disaster or accident. In addition, in Figures 4 and 5, ■ indicates the subscriber side, ■
2 is a relay station, 22 is an exchange main body, 23 is a relay type, and 24 is a telephone set.

<Effects of the Invention> As specifically explained above in conjunction with the embodiments, according to the present invention, when the synchronization signal is interrupted for a long time, each part of the subscriber circuit is controlled using a predetermined fixed data pattern. Therefore, it is possible to perform appropriate control by releasing the latch state of the control corresponding to the control data immediately before the synchronization signal is interrupted.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a first embodiment of the invention, FIG. 2 is a block diagram showing a second embodiment of the invention, and FIG. 3 is a block diagram showing a second embodiment of the invention.
The figure is a block diagram showing a third embodiment of the present invention, FIGS. 4 and 5 are block diagrams showing systems to which the first to third embodiments are applied, and FIG. 6 is a block diagram of a subscriber circuit. FIG. 7 is a block diagram showing the entire system, and FIG. 7 is a block diagram showing extracted control sections according to the prior art. In the drawing, 1 is a telephone, 3 is an RT function section, 4 is a BSH function section, 5 is an encoding/decoding section, 6 is a control section, 7 is a PCM highway, 9a and 9b are latch registers, 14.16 is a timer , 15.18 is an output section, S is a beam set signal, and S2 is a selection signal.

Claims (1)

[Scope of Claims] The control signal supplied via the PCM highway is taken in based on the synchronization signal to control various functional units that perform processes such as sending a ringing signal and supplying talking current to the telephone, and the synchronization signal is In a control device for a subscriber circuit, which is configured to latch the control state immediately before the interruption when the control state is interrupted, there is provided a timer means for sending out a selection signal after a set time has elapsed using the synchronization signal as a reset signal; an output section that sends control data based on the control signal to each functional section, and also sends fixed data, which is control data including predetermined control contents, to each functional section upon input of a selection signal; A subscriber circuit control device comprising: