SU555555A1 - The device receiving frequency-manipulated signals - Google Patents

Claims (2)

(54) DEVICE FOR ACCEPTANCE OF FREQUENCY-MANIPULATED SIGNALS output 10 - output failure. The input of receiver 1 is connected to a pin. The malfunction detection unit 4 (see Fig. 2) is sucking from the first element 11 11 connected in series, the first trigger 12, the second element 13 and the element 11 and the output 14 of which is connected to; the installation inputs of the first and second triggers 12 and 15, and the output of the second trigger 15 is connected to the input of the first element 11, the second input of which is connected to the first information input 7 of block 4, the second information input 8 of which is connected to the inputs of the second element 13 and second trigger 15. The second input of the OR element 14 is the installation input 9 of unit 4, and the output of the AND element 13 is the output 10 failure. The device operates as follows. From the communication line, synchronized-manipulated signals are received (in Fig. 2, the initial binary signals at the input of the transmitting device, Fig. 3) In the frequency-manipulated signals at the input of the communication line at the transmitting end}, which, due to their interference in the communication line, differ from the transmitted ones, are sent to the receiver 1, which is essentially an amplifier-limiter that converts the incoming sinusoidal signals (or similar in shape to sinusoidal signals). the corresponding impulses of a rectangular shape (Fig. 3 Z From the output of receiver 1, the pulses arrive at the input of decoding unit 2, where the clock frequency of the information pulses is allocated, the received signal is gated, the received signal is resolved to one of two values ( zero or one, and the sequence of pulses thus obtained is converted into a parallel code corresponding to the transmitted word combination. The latter arrives at the output bus 3 data. From the output of receiver 1, the pulses simultaneously arrive at the input of the differentiating circuit 5, at the output of which, at the moment of crossing, the input signal of the zero axis appears short pulses, which then enter the input of digital filter 6 (Fig. 3 which works in such a way that (input 7 of block 4) an impulse appears if the duration of the half-cycle of the input signal corresponds to the upper operating frequency (or close to this duration), and at the other output - in the case (input 8 of block 4) if the half-period of the input signal This corresponds to the lower working frequency (or is close to this length. When transmitting over a lower operating frequency at the input 8 of block 4, pulses appear at the installation input of the trigger unit 15 and at the And 13 element. In the initial state Triggers 12 and 15 are in the zero state, which is provided by supplying a start of operation of the corresponding pulse to input 9. A pulse received at input 8 of block 4 transfers trigger 15 to the state of unity. Upon receipt of subsequent pulses at input 8, the status of trigger 15 is confirmed. Then at the output of the element And 13, i.e. the output 10 fails, there are no signals, since their passage is prohibited by the zero initial state of trigger 12. When the polarity of the original manipulating signal is changed, the transmitted frequency also changes accordingly. Then the pulses will be fed to the input 7 of block 4 (Fig. 3 e. The latter pass through the open single state of the trigger 15 element 11 and arrive at the counting input of the trigger 12, which is transferred by the first pulse to the single state. In Fig. Zh - pulses at input 8 of block 4, in Fig. 3, I and 3 a are pulses at the outputs of flip-flops 15 and 12, respectively, which are in the unit state. With an undistorted input-frequency-manipulated signal, the number of consecutive pulses at input 7 must be an even Second pulse 12 throwing The next pulse can appear both at input 7 and at input 8. Both appear to be resolved. In the presence of interference on the communication line, which significantly distorts the signal, block 4, that monitors the correctness of the occurrence of the upper or lower frequency, a failure can be detected, which indicates a low reliability of the received information. For example, a failure will be detected if the transmission of the signal of the upper operating frequency of the last three half-periods before switching the signal to the bottom th operating frequency of the first two will be transformed interference between the lower operating frequency or at a lower operating frequency transmission signal luperioda last two orders of interference will be transformed into one half and the lower operating frequency in the upper two - etc. (on fig.Z-g is marked). If the number of pulses arriving at the input 7 in the gap between the pulses arriving at the input 8 is odd, which indicates that the signal is disturbed by an interference, then at the moment of arrival of the pulse at the input 8, the trigger 12 will be in one state, i.e. the prohibition of the passage of the digital filter 6 to the input 8 through the trigger 12, and the output U through the pulse, indicating the presence of a fault in the received sequence of information signals (Fig, Зк) will be removed. By the same impulse, the failure detection unit 4 is reset to the initial state, since the pulse through the element OR 14 goes to the setup inputs zero of the flip-flops 12 and 15. The pulse duration at the output 10 is equal to the sum of the switching time of the elements And 13, IL 14, and trigger 12. It is especially effective to detect failures during long-term interference (bursts of interference) when the violation the pulse arrival sequence detected by block 4 is more likely. Thus, the detection of a failing situation makes it possible to increase the reliability of the received information without taking up either an additional channel bandwidth or entering redundant verification information in the message. Claim 1. A device for receiving frequency-manipulated signals, comprising a receiver connected to a decoding unit, characterized in that, in order to improve noise immunity, a failure detection unit and a serially connected differentiating circuit and digital filter are inserted, the receiver output being connected to a differentiating circuit and the digital filter outputs are connected respectively to the first and second information inputs of the failure detection unit. 2. The device according to claim 1, on. so that the failure detection unit consists of the first AND element, the first trigger, the second AND element, and the OR element, whose output is connected to the setup inputs of the first and second triggers, and the output of the second the trigger is connected to the input of the first element AND, the second input of which is connected to the first information input of the failure detection unit, the second information input of which is connected to the input of the second element AND, and the second input of the OR element is the installation input of the detecting block and failures. 9 HiJfuHua Sat zi YU 2 L L L A. l And h ch l. 1 v y vy v v g j vy LPL GiLG11I1 PG1Gi