SU698158A1 - Device for automatic selection of the rate of reception of facsimile apparatus - Google Patents

Description

one

The invention relates to radio engineering and can be used to automatically select the speed of a receiving fax machine when working on digital kanshgu.

A device for automatically selecting a receiving fax speed is known, comprising a trigger, n reference pulse generators, a first and second time relay, an adder, a start counting key, and a control unit, the trigger output being connected to the first inputs n of the reference pulse generators and to the first input of the first relay. time, the second input of which is connected to the output of the second time relay and to the second input of the start of account key, and the output of the first time relay is connected to the second inputs n of the reference pulse generators and to the second Swipe at the trigger input, the adder output is connected to the input of the second time relay and to the first input of the start of account key, the output of which is connected to the corresponding input of the control unit 1.

Odaako known device has low speed and noise immunity.

The purpose of the invention is to increase the speed and noise immunity.

For this, the device for automatic selection of the speed of the receiving facsimile unit containing the trigger, n reference pulse generators, the first and second time relay, the adder, the start key and the control unit, the trigger output connected to the first inputs of the reference pulse generator n and to the first input the first time relay, the second input of which is connected to the output of the second time relay and to the second input of the start account key, and the output of the first time relay is connected to the second inputs n of the reference pulse generators and to volts to the trigger input, the output of the adder is connected to the input of the second time relay, and the phase pulse discriminator and the pulse train B are inputted to the first input of the second time switch, entered sequentially connected by a discriminator of phase pulses ti, block of irregularities and e.g emeng OR. Vyhots ireobrazovatel of a series of pulses in a single connected to the first input of the trigger and to the first inputs of the time selectors, to the second inputs of which are connected n generators of the reference pulses, respectively. The outputs of the n time selectors are connected to the corresponding inputs of the adder and to the first inputs of the memory nsters, to the second inputs of which through the OR element connect the output of the first time relay. The codes of the memory triggers are connected to the corresponding inputs of the control unit and the inequality block, the output of which is connected to the corresponding input of the OR element.

The drawing shows the structural electrical circuit of the prepositioned device.

The device for automatic selection of the speed of the receiving fax machine contains a discriminator 1 phase pulses converter 2 series of pulses into a single, trigger 3, adder 4, n time selectors 5, n generators b standard impulses, first 7 and second 8 time relays, counting switch 9, n memory triggers 10, unequal unit 11, an OR element 12 and a control unit 13 consisting of a counter 14, n keys of an IS executive relay and n executive relays. sixteen.

A device for automatically selecting the speed of a receiving fax machine operates as follows.

The first incoming series of phase pulses is made in the discriminator 1 of the phase pulses and J is fed to the input of the converter 2 series of pulses into a single one, at the output of which a single square pulse appears whose duration is equal to the duration of the series of phase pulses. This one arrives at the corresponding inputs of the time selectors 5 and simultaneously triggers trigger 3, which starts the first time relay 7 and generators 6 reference pulses. Each generator of 6 reference pulses produces a sequence of reference pulses, the duration of which corresponds to the selected reception rate of the T1 channel for the i-th speed (i I, 2, ..., p). These sequences arrive at the corresponding inputs of the time selectors 5, in which the comparison of the periods of the reference pulses from the generators b of the reference pulses and the pulses coming from the converter 2 series of pulses into a single one takes place. A time selector 5, in which the duration of the indicated pulses coincides, triggers and pulses through the adder 4 to the second time relay 8 and oversets the corresponding trigger 10 of the memory. The second time relay 8 starts up, opens the counting key 9, and allows the pulses to arrive at the gate 14 input. When calculating a certain number of pulses at the output. counter 14, a signal appears that opens the keys of the 15 executive relays, and the signal from the output of the memory trigger 10 through the corresponding key 15 of the executive relay turns on the corresponding executive relay 16 of the control unit 13.

The first time relay 7 is provided for switching off the device in the event that the latter is triggered by a false pulse from the converter 2 series of pulses into a single pulse. The response time of the first time relay 7 is somewhat selected, the longest of the largest period following the phase pulse groups. Therefore, when a spurious pulse arrives at the input, the generators 6 reference pulses and the first time relay 7 turn on, but since none of the time selectors 5 match the pulses happens, the second time relay 8 does not start. After the time of operation of the first time relay 7 expires, a reset is applied to the trigger 3, the generators 6 reference pulses and through the OR element 12 to the memory triggers 10, which brings the device to its initial state. In the case of selection of several speeds at once, the block 11 of unequalities is triggered and through the element OR 12 clears the trigger 10 of the memory, and the choice of speed begins again. In the case of switching on the second time relay 8 from the source pulse and the operation of the counter 14, the first time relay 7 is blocked in the off state and remains there until the second time relay 8 ends, after which the trigger 3 is turned off, the memory trigger 10 and generators b reference pulses to the initial state.

The proposed device allows automatic selection of the speed of the facsimile receiving device when working on a digital channel and increases the noise immunity of the device by determining the correctness of the selected speed, both by comparing the conversion pulse from a series of phase pulses with reference pulses in time selectors 5 and by the number of correctly calculated phase pulses in the counter 14. The speed will increase significantly.

Claims (1)

1. USSR author's certificate P 418988, cl. H 04 N 1/36, 1972 (prototype).