JPS5871762A - Subscriber circuit of terminal device exclusive for incoming call - Google Patents

Abstract

PURPOSE:To store an existing terminal exclusive for incoming call into a time division switchboard without reconstruction, by controlling a current supplying circuit with the output of an AND of the negtive conditions of a control line for reduction of power consumption and the affirmative conditions of a control line for the current supplying circuit. CONSTITUTION:A control program of a central processing controller 11 drives both a power consumption reduction control line 6 and a current supplying circuit control line 7 when a terminal T is free. Thus a general subscriber terminal SUB has an originating call, and this call is detected by a loop monitor circuit 5 if a short circuit is secured for the DC resistance between lines A and B. For a subscriber circuit 12 of the terminal exclusive for incoming call, a current supplying circuit 4 is controlled with the output of an AND circuit 13 of the negative conditions of the line 6 and the affirmative conditions of the line 7. Thus the circuit 4 of the circuit 12 is turned off although the control program drives the lines 6 and 7 when the terminal is free and regardless of a general terminal or the terminal 12 exclusive for incoming call. As a result, no current is supplied even with a connection of the terminal T short-circuited between the lines A and B in the normal mode. Thus it is avoided that a loop is detected by the circuit and then regarded as an originating call.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a subscriber circuit for a terminal exclusively for receiving calls in a time-division exchange. Explain: Figure 1 is a subscriber circuit diagram of a terminal exclusively for incoming calls in a space-division exchange, and Figure 2 is a circuit diagram of a terminal for incoming calls only in a time-division exchange. As shown in Figure 1, the terminal subscriber circuit has a loop monitoring circuit AB.
Since the configuration is such that it is not connected to the li, even if the AB line is short-circuited with low DC resistance when the incoming call-only terminal device T is accommodated, loop monitoring is possible, that is, the control program of the central control unit allows the incoming call-only terminal device T to be connected. Even if you are not aware of the subscriber class of the terminal, it will not be mistakenly assumed to be a call detection.In addition, the loop monitoring of the terminal device T after it enters a call state is performed by the call trunk 'TRK'. , the system was such that when an abnormality occurred at the incoming call terminal T, if the short circuit of the low DC resistance of AB@Seki disappeared, this was detected in the call trunk TRK.

As shown in Fig. 2, the subscriber circuit for incoming calls in the time-division exchange is configured to supply a smear current from the subscriber circuit 1.
If there is a short circuit between the lines, the subscriber circuit 1 will be confused and make a call. Also, whether the receiving terminal T is empty or in use is not known on the receiving terminal side, but is known on the exchange TD side. Therefore, it is necessary to provide a control line 8 from the central control unit 11 to the incoming terminal T at 9:00 to open the short circuit caused by the low direct current resistance between the A and B thin wires at the incoming terminal T. As described above, the incoming call terminal subscriber circuit 1 in the time division switch TD has drawbacks such as the need to modify the existing incoming call terminal T. In the figure, 2 is an encoding circuit, 3 is a 2-wire/4-wire conversion circuit, 4 is a current supply circuit, 5 is a circuit for monitoring the terminal device loop, 6 is a control line for saving power consumption, and 7 is a current The control line of the supply circuit, 9 is the idle control circuit of the incoming terminal, and 10 is the AB line DC low resistance short circuit.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to provide a subscriber circuit capable of accommodating a terminal exclusively for receiving calls without the control program of a central control unit being aware of the subscriber classes of general terminals and terminals exclusively for receiving calls. It provides:

The subscriber circuit of the present invention controls the current supply circuit from the control device via a two-manpower AND circuit. In particular, the output side of the two-manpower AND circuit is connected to the current supply circuit, and its input The negative condition of the power consumption saving control line and the positive condition of the current supply circuit control line of the control device are connected to the side.

Next, referring to FIG. 3, one embodiment of the incoming terminal subscriber circuit according to the present invention will be described. In FIG. 3, the incoming call terminal T is connected to the subscriber circuit 12 through the AB line,
A current supply circuit for a terminal subscriber circuit 12 exclusively for 0-incoming calls, which has a short circuit 10 that is connected with a short circuit 10 that shorts the A and B thin wires with a low DC resistance in a normal state, and is connected to an open circuit between the A and B thin wires in an abnormal state. 4 is an O-10,000 general subscriber circuit 1 driven by an AND circuit 13 of the negative condition of the power consumption saving control line 6 and the positive condition of the current supply circuit control line 7. It is used to cut off power to circuits other than the supply circuit 4 and loop monitoring circuit 5. The power supply circuit control line is used to control the power supply circuit ◇ Also, the control program of the central control unit [11] drives the power consumption saving control @6 and the current supply circuit control line 7 at 9 o'clock on terminal T. do. Therefore, in the general subscriber circuit I, the consumption 'power saving control IIi! 3. 2!4fil change circuit which is unnecessary when the 6 is empty. Also, the current supply circuit 4 is driven by the current supply circuit control line 7, and therefore the general subscriber terminal 5LAB generates a low DC resistance between the A and B thin wires. If a short circuit is established, current is supplied and the loop monitoring circuit 5 detects a call. In the incoming terminal subscriber circuit 12, the AND circuit 13 of the negative condition of the above-mentioned power consumption saving control) 16 and the positive condition of the current supply circuit control line 7 is executed without distinguishing between the general terminal 1 and the incoming terminal 12. Both controls above at 9 o'clock on the terminal -6
゜7t-J1! Terminal subscriber circuit 12 dedicated for incoming calls even if h is activated
The current supply circuit 4 is turned off. Therefore, in a normal state, even if a terminal T for incoming calls is connected, in which A and B are short-circuited with a low DC resistance, no current is supplied to the terminal, so the loop monitoring circuit 5 detects a loop. As explained above, by controlling the current supply circuit with the output of the logical product of the negative condition of the power consumption saving side Ha and the positive condition of the current supply circuit control line, the subscriber class of the general terminal and the incoming call terminal can be determined by the control program. There is no need to separate the subscriber circuits for general and incoming call terminals:i
It is also economical in terms of the system, as it can be controlled and accommodated in a time-division exchange without modifying existing terminals for incoming calls.

[Brief explanation of drawings]

The second factor in FIG. 1 is a subscriber circuit diagram for a conventional terminal device exclusively for receiving calls, and FIG. 3 is a subscriber circuit diagram for a terminal device exclusively for receiving calls according to the present invention. 1... General subscriber circuit, 2... Encoding circuit, 3... 2-wire 4-wire conversion circuit, 4...
...Current supply circuit, 5...Loop monitoring circuit, 6
......Power consumption saving control line, 7...'#
It flow supply circuit control line, 8... 9 o'clock control line for incoming terminal only, 9... Incoming terminal empty control circuit for incoming terminal, 1
0...AB line DC low resistance short circuit, 11...
. . . Central control unit, 12 . . . Terminal subscriber circuit dedicated to incoming calls, 13 . . . AND circuit. Atsushi 1 Atsushi Z diagram

Claims (1)

[Claims] In a subscriber circuit that includes a current supply circuit, a loop monitoring circuit, a 2-wire 4-wire conversion circuit, and an encoding circuit in a time division exchange, a power consumption saving control line from a control device is connected to the 2-wire 4M conversion circuit and the encoding circuit. The output of the two-manpower AND circuit is connected to the current supply circuit, and the input of the two-manpower AND circuit is connected to the negative condition of the power consumption saving control line and the current supply circuit control of the control device. Subscriber circuit O of a terminal device exclusively for incoming calls, characterized in that the positive condition of the line is connected