JPH0410843A - Non-communication time signal supply system for subscriber circuit - Google Patents

Abstract

PURPOSE:To send a non-communication time signal to a terminal equipment from a subscriber circuit without occupying a time slot on a communication bus by providing a non-communication time signal generating source to the terminal equipment accommodated to the subscriber circuit. CONSTITUTION:A subscriber circuit 20 connecting to a communication bus 10 accommodates subscriber terminal equipments through a subscriber line 30. The subscriber circuit 20 is provided with a microprocessor 21, a time slot multiplex section 22, a time slot extraction section 23 and a terminal interface section 24, and a line switch section 25 in addition. In this case, a line switch section 25 of each subscriber circuit 20 has all kinds of non-communication time signal registers required for terminal equipments accommodated in the line switch section 25. thus, it is not required for a time slot on a communication bus 10 to send a non-communication time signal and the time slot is assigned to all communication information.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides a system for connecting subscribers to a communication bus for transmitting time-division multiplexed information until they are assigned a time slot for communication under the control of a microprocessor. The present invention relates to a no-communication signal supply system in which a circuit supplies a no-communication signal to a terminal via a subscriber line.

[Conventional technology]

Conventionally, in this type of no-communication signal supply system, the no-communication signal is transferred to a predetermined time slot of the communication bus.
By designating a predetermined time slot for each terminal by the microprocessor, a predetermined no-communication signal is supplied from the subscriber circuit to the terminal via the subscriber line.

This will be explained with reference to FIG. FIG. 2 is a block diagram showing a conventional example.

As shown in FIG. 2, the subscriber circuit 90 is connected to the communication bus 10 and has an interface function with the terminal 40 accommodated via the subscriber line 30. The communication bus 10 is a communication path using a time division multiplexing method that divides and extracts communication data and information into time slots within one frame. Transmit.

In recent years, terminals interface with exchanges, and in addition to the A-law (LAW) and μ-law (LAW) signals associated with conventional telephones, diversified data terminals have put into practical use a wide variety of signal formats.

Therefore, when connecting terminals of any type, all types of no-communication signals for connectable terminals are required. That is, as shown in FIG. 3 showing a data frame on the communication bus 10, a predetermined number of time slots (for example) 1, 2, .
It has B...

The subscriber circuit 90 includes a microprocessor 91.timeslot multiplexer 22. It has a time slot extraction section 23 and a terminal interface section 24. The microprocessor 91 makes full use of the data received in response to the control signal and the pre-stored programs and data to perform the time slot multiplexing section 22 and the time slot extracting section 2.
Control 3. The time slot multiplexing unit 22
The communication information transmitted from IO is time-division multiplexed into the time slots of the communication bus IO under the control of the microprocessor 91 and transmitted. The time slot extractor 23 extracts specified communication information from the time slot of the communication bus 10 under the control of the microprocessor 91 and transmits it to the terminal 40 .

The terminal interface section 24 procures interconnection conditions for connecting the subscriber circuit 90 to the terminal 40 via the subscriber line 30.

When transmitting a no-communication signal from the subscriber circuit 90 to the terminal 40, when the microprocessor 91 specifies a predetermined no-communication signal time slot on the communication bus 10, for example, time slot 2, the control of the microprocessor 91 Accordingly, the time slot extracting section 23 extracts the no-communication signal from the time slot 2 and transmits it to the terminal 40 via the terminal interface section 24 and the subscriber line 30.

[Problem to be solved by the invention]

As mentioned above, in the conventional no-communication signal supply system, the subscriber circuit extracts a predetermined no-communication signal from the no-communication signal time slot on the communication bus and supplies it to the terminal. Not only is a time slot for idle signals required on the communication bus, but the diversification of communication methods for connecting to subscriber lines has led to an increase in the number of time slots for idle signals. There is a problem in that the number of time slots for communication is reduced, which puts pressure on communication capacity.

An object of the present invention is to provide a signal supply system during no communication which solves the above problems.

[Means to solve the problem]

The basic structure of the signal supply system for subscriber circuits when there is no communication according to the present invention is that the subscriber circuits wait until a time slot for communication is assigned under the control of a microprocessor on a communication bus that transmits time-division multiplexed information. In the idle signal supply method, which supplies a idle signal to a terminal via a subscriber line, at least one idle signal is driven by the microprocessor to generate a idle signal to the subscriber line. A time signal register is provided in the subscriber circuit.

Further, one of the specific configurations of the signal supply means of this system is that the subscriber circuit controls the pressure of all the built-in no-communication signal registers and the predetermined time slot position extracted from the communication bus. The present invention includes a selector which takes information output as an input, selects one of the plurality of inputs under control of the microprocessor, and outputs the selected one to the subscriber line.

The no-communication signal supply system of the present invention using the above-mentioned means allows the no-communication signal to be supplied to the terminal from within the subscriber circuit rather than from the time slot on the communication bus.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. As shown in FIG. 1, a subscriber circuit 20 connected to the communication bus 1o is connected to a subscriber terminal (not shown) via a subscriber line 3o.
It accommodates and connects.

The subscriber circuit 20 includes a microprocessor 21 (time slot) li converter 22 . In addition to the time slot extraction section 23 and the terminal interface section 24, the line switch section 2
5. In FIG. 1, the same components as those shown in the previously described conventional example (FIG. 2) are given the same numbers and symbols, and their explanations will be omitted.

The microprocessor 21 receives control signals from the terminal and the exchange, and controls the time slot multiplexer 22 to transmit information transmitted from the terminal to the communication bus l.

multiplexed and transmitted. On the other hand, microprocessor 2
1 is a time slot extraction unit 23 and a line switch unit 2
5 to transmit the received information from the time slot on the communication bus lo to the receiving terminal, and also transmit a no-communication signal when there is no communication.

The line switch unit 25 has a non-communication signal A register 26.
It has a non-communication signal B register 27 and a selector 28. The no-communication signal A register 26 is the no-communication signal A.
Send. The no-communication signal B register 27 transmits the no-communication signal B. The selector 28 receives as inputs the outputs of the time slot extractor 23 and a plurality of signal registers including the no-communication signal A register 26 and the no-communication signal B register 27, and selects one of the inputs under the control of the microprocessor 21. and outputs it to the terminal interface section 24.

When the microprocessor 21 transmits the no-communication signal A to the subscriber line 30, it drives the no-communication signal A register 26 and the selector 28 to send the output of the no-communication signal A register 26 through the terminal interface section 24. subscriber line 30
Send to.

Furthermore, when connecting communication information to a terminal, the microprocessor 21 includes a time slot extractor 23 and a selector 2.
8 to transmit the output of the time slot extraction section 23 to the subscriber line 30 via the terminal interface section 24.

According to this embodiment, the line switch unit 25 of each subscriber circuit 200 has all types of no-communication signal registers required by the terminals it accommodates, so that the time slots on the communication bus 10 receive no-communication signals. Since there is no need to transmit it, it is all allocated to communication information.

According to this embodiment, the selector has been illustrated and explained as selecting and outputting the no-communication signal and the communication information under the control of the microprocessor, but in this embodiment, the selector may be a gate circuit under the control of the microprocessor. Although the registers 26 and 27 store the no-communication signal and the microprocessor 21 instructs the output, a selector or gate circuit is added to the signal output from the no-communication signal generator according to instructions from the processor. It may also be output to the public line.

〔Effect of the invention〕

As explained above, the no-communication signal supply system of the present invention has a structure in which the subscriber circuit is provided with a no-communication signal generation source for the terminals accommodated, so that the time slot on the communication bus is There is an effect that a signal during no communication can be transmitted from the subscriber circuit to the terminal without occupying the circuit.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a conventional example, and FIG. 3 is a block diagram showing an example of a conventional data frame. 10... Communication bus, 20... Subscriber circuit, 21... Microprocessor, 23... River...
・Time slot extraction unit, 25...Line switch unit, 26.27...No communication signal register, 28.
...Selector, 3゜...Subscriber line, 40.
...Terminal. Agent Patent Attorney Hara Uchi

Claims (2)

[Claims] (1) Until a time slot for communication is assigned under the control of a microprocessor on a communication bus that transmits time-division multiplexed information, the subscriber circuit sends a no-communication signal to the terminal via the subscriber line. In the no-communication signal supply method, the subscriber circuit is provided with at least one no-communication signal register that is driven by the microprocessor and generates a no-communication signal to the subscriber line. A system for supplying signals to subscriber circuits when there is no communication. (2) The subscriber circuit receives as input the outputs of all the built-in no-communication signal registers and the information output of a predetermined time slot position extracted from the communication bus, and receives multiple signals under the control of the microprocessor. 2. A system for supplying a signal during no communication to a subscriber circuit according to claim 1, further comprising a selector for selecting one of said inputs and outputting the selected one to said subscriber line.