RU1774516C - Device for controlling and checking of command transmission over telephone lines - Google Patents

Abstract

The invention relates to control and monitoring devices for transmitting commands via telephone lines and can be used on telephone networks. The goal - improving operational reliability by increasing the noise immunity of the direct information channel signal - is achieved by introducing, on the side of the executive unit, a second generator 9, a control signal selector, a transmit-receive unit and a call confirmation unit. 1 ill.

Description

The invention relates to telecommunications and can be used in telephone communication systems integrated with control command transmission systems.

The purpose of the invention is to increase reliability by increasing the noise immunity of a direct data channel signal.

The drawing shows a structural electrical diagram of a device for controlling and monitoring the transmission of commands over telephone lines.

The device comprises first and second control units 1 and 2, a first generator 3, a call receiving unit 4, a line disconnect unit 5, an answering machine 6, a switching unit 7, a contactor 8, a second generator 9, a control signal selector 10, a receiving unit 11 transmission, block 12 confirmation of the correct call, telephone dispatcher 13, automatic telephone

station 15, telephone 16 subscribers.

A device for controlling and monitoring the transmission of commands over telephone lines operates as follows.

The dispatcher, using the telephone set 13, dials the number of the telephone set 15. An automatic telephone exchange (PBX) 14 connects the calling line to the called line and sends a call signal through it using an inductor. The call signal, passed through the line, enters block 4 connected to the communication line parallel to telephone set 15. Block 4 acts on block 5, which automatically connects block 11 to the line, which is equivalent to the raised state of the telephone set’s handset, and the telephone exchange disconnects your inductor.

Block 12 generates, through blocks 11 and 5, a response signal with a frequency of 300 Hz, which is heard in the handset of the telephone set V4 XI 4 СЛ

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that 13 dispatchers. In addition, block 12 includes a call. If the subscriber picks up the telephone, the device is disconnected by unit 5 from the line. When using the device for its intended purpose, the dispatcher presses a button in the second block 2, and the first generator generates a sinusoidal parcel with a frequency of 2 kHz per line. This signal, passing through block 5, enters block 11, where it is converted into a train of pulses with a sine wave frequency.

In the selector 10, the pulse repetition time is checked, and if it is equal to 2 kHz, this sequence is converted into a potential signal, the duration of which is determined by the time the button is pressed by the dispatcher. The signal of the 2 kHz reference frequency is generated by the second generator 9. The potential signal corresponding to the first pressing of the button by the dispatcher from block 10 passes to the first block 1, where it is stored. By this command, which passed from block 1 to block 12, the signal confirming the correctness of the call to the line ceases to be generated, and the call is disconnected. In addition, the signal generated by block 1 at the first press of a button allows the answering machine 6 to work, which sends a continuous sequence of pulses with a frequency of 750 Hz or an intermittent sequence, depending on the state of contactor 8, through blocks 11 and 5 in line. The dispatcher, listening to these signals in the handset of the telephone 13, determines the state of the contactor and presses the button again in block 2. This signal through blocks 5, 11, 10 comes to block 1, where it is memorized and triggers the switching block 7, which leads to in turn, to a change in the state of contactor 8. Block 1, having received information from block 7, generates a command in block 6, where the form of the response signal changes in accordance with the change in state of contactor 8.

Claims (1)

SUMMARY OF THE INVENTION A device for controlling and monitoring the transmission of commands over telephone lines, comprising serially connected a first control unit, a switching unit and a contactor connected in series to a first generator and a second control unit connected to a telephone line of a dispatcher telephone, a series-connected answering machine and a line disconnect unit, the second input of which is connected to the output of the call receiving unit connected to the telephone line of the subscriber’s telephone, which, in order to increase reliability by increasing the noise immunity of the signal of the information channel, a transmit-receive block, a second generator, a call confirmation block, and a control signal selector are introduced, the first input of which is connected to the output of the second generator, the input of which is combined with Odom selector control signal and connected to the first output receive-transmit unit, the first input of which is connected to the output of the call confirmation unit, the first input of which is connected to the second output of the answering machine, the third output of which is connected to the second input of the receive-transmit unit, the second output of which is connected to the telephone line of the subscriber’s telephone set, k of which the second input of the line disconnect unit is connected, the output of which is connected to the third input of the transmit-receive unit, the second output of the switching unit being connected to the first input of the first control unit, the second Exit of which is connected to the second input 0 of the block confirming the correctness of the call, the third input of which is connected to the second output of the second generator, the third output of which is connected to the first input of the answering machine, the second input of which is connected to 5 by the third output of the first control unit, the second input of which is connected to the output of the control signal selector,