SU1755311A1 - Device for interrogation of controlled stations - Google Patents

Abstract

The invention relates to a technique for transmitting information in automated process control systems of industrial enterprises and can be used for automated greenhouses. The aim of the invention is to increase the reliability and informational flexibility of the device due to the possibility of organizing a survey from any switching unit. The device contains ONE Control point 1, several switching units 2-5, several executive elements 6-13, several starting elements 14-16, one communication line 17-22, 2 Il.

Description

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The invention relates to the transfer of information in automated process control systems of industrial enterprises and can be used in automated control systems for greenhouse plants.

A device for polling control objects is known, which contains a control point (PU), spaced apart distributor relays, grouped into controlled points (KP), and a communication line consisting of a common bus, four busses of motion, and a start bus.

The disadvantages of this device are: lack of reliability due to the impossibility of polling the CP, whose objects are between the failed relays; device failure when the first and last relays fail; the inability to organize the beginning of the survey with any relay, except the first.

It is also known a device for polling measurement and alarm objects, comprising common and three alternately switched traffic buses, electromagnetic relays controlled by clock pulses, and forward and reverse start buttons.

The disadvantages of this device are; lack of reliability of operation of the device, since it does not ensure interrogation of objects between gearboxes whose relay failed; the inability to organize a survey KP of choice; device failure when the first and last relays fail,

Closest to the present invention is a device for polling measurement and signaling objects, comprising PU, execution units, start-up units and a communication line consisting of a common bus, three traffic buses, two call buses and an alarm bus.

The drawbacks of the device are: low reliability and informational flexibility due to the impossibility of organizing a survey from any executive unit; the use of two call buses for controlling the starting blocks, which increases the number of cores in the communication cable.

The purpose of the invention is to increase reliability and information flexibility due to the possibility of organizing a survey from any switching unit,

Fig. 1 is a schematic diagram of the device 1 in Fig. 2, a diagram of a control point.

The device comprises a control point 1, switching blocks 2-5, consisting of actuators 6-13, start elements 14-16, a communication line including a common bus 17, a movement bus 18-20, a direct start bus 21, bus 22 reverse start.

The control point contains a block 23 for starting and shaping pulses, the first group of 24 elements AND, the second group 25 elements And, the third group 26 elements And, call buttons 27-32, elements OR 33-35, drivers 36-38 pulses, button 39 direct start button 40

0 reverse start, amplifiers 41 and 42, power supply terminal 43.

The starting and forming unit of the impulses of movement consists of a switch key 44, a reset button 45, a generator 46

5 pulses, a counter on two triggers 47 and 48, a decoder 49, a switch with contacts 50 and 51, amplifiers 52-54, buses 55-57.

The first group of elements and includes

0 elements And 58-60, in the second - elements And 61-63, in the third - elements And 64-66.

The device works as follows.

To turn on the device closes

5, the key 44 (FIG. 2) and the power is supplied to the common bus of the communication line 17 and the input of the pulse generator 46, which begins to form a continuous sequence of pulses at the counter input (flip-flops 47 and 48).

0 As a result, negative-polarity clocks alternately appear at the outputs of the decoder 49, which are fed to the contacts 50 and 51 of the switch. The latter can be in two positions - the first or the second. In the first position of the switch, the device operates in the direct start mode (polling of objects starts from the first switching unit), in the second, in reverse mode (polling of objects starts from the last switching unit). Therefore, depending on the position of the switch, the clock pulses are fed alternately to the inputs of amplifiers 52-54 and further to the buses

5 movements 18-20 of the communication line and the inputs of the first group of elements I (26), as well as directly to the first terminals of the buttons 27-32 in the forward or inverse order,

Despite the fact that the common bus line

0 connection is connected to the minus of the power source, and positive-polarity clock pulses are received on the busses, the objects are not polled because the first relay 6 of the first switching unit 2, or the last relay 13 of the last switching unit 5, or the relay one of the elements 14-16 run (optional polling mode).

For a direct interrogation of objects, the direct start button 39 is pressed, as a result

of which a negative polarity clock pulse is supplied to the amplifier 41 and further to the bus 21 of the direct start of the communication line. Thus, in the first cycle, a positive impulse will flow to the first bus 18 of movement, and a negative pulse to the bus 21 of direct start. In this case, the first actuator 6 of the first switching unit 2 (Fig. 1) will trigger the relay, since different polarity pulses are received at both ends of its windings. The relay becomes self-blocking and closes its contacts in the relay circuit of the subsequent actuator, preparing it for actuation. At the same time, through the other contacts of the relay, the survey of the first control object begins.

At the next cycle, a positive potential appears on the second bus line 19 and the relay of the second actuator is triggered, since the contacts of the relay of the previous actuator 6 were closed at the first cycle. The relay becomes self-blocking, closes its contacts in the relay circuit of the subsequent actuator and begins polling the second control object. Similarly, the device works on other cycles.

To reverse the polling of the objects, the switch is set to the second position and the reverse start button 40 is pressed. As a result, a negative-polarity clock pulse is supplied to the amplifier 42 and further to the bus 22 of the reverse start of the communication line. Thus, in the first cycle, a positive impulse will come from the amplifier 54 to the third bus 20, and a negative impulse to the bus 22 of the reverse start. At the last actuator 13 of the last switching unit 5 (FIG. 1) the relay will work, since both ends its windings receive opposite polarity pulses. The relay becomes self-blocking and closes its contacts in the relay circuit of the previous actuator, preparing it for actuation. At the same time, through the other contacts of the relay, the last control object is polled

On the next cycle, a positive potential appears on the second bus 19 of the line of communication and works out the relay of the penultimate actuator, since the contacts of the relay of the last actuator 13 were closed in the previous cycle. The relay becomes self-blocking, closes its contacts in the relay circuit of the previous actuator and begins polling the penultimate control object. Similarly, the device operates on other cycles. To interrogate objects of choice, for example, direct interrogation from the second block of 3 mutations, the switch is set to the first position and the call button 27 of the first launch element 14 is pressed.

At the same time, in the first cycle from the start-up unit and the formation of motion impulses, a positive polarity pulse is supplied to the first bus 18 of the communication line from the amplifier 52, negative potentials to the buses 56 and 57 from the amplifiers

5 53 and 54 and a negative polarity pulse to the first input of the circuit And 58 through the button 27, At the same time, to the second input of the circuit receives a negative potential from the output of the circuit 64, which is triggered by

0 negative potentials on buses 56 and 57. As a result, AND 58 opens and issues a signal to the driver 37 through pulses OR 34 which generates a negative start pulse

5 polarity, arriving at the second bus line 19. In this case, the relay of the starting element 14 is actuated, since a positive impulse is fed to one winding of its winding through the first bus of movement

0 lines of communication, and on the other its output is negative on the second bus line. The relay becomes self-blocking, closes its contacts in the circuit of the actuating element 8, preparing it to operate

5 at the next clock cycle, and the survey of the corresponding control object begins. In the second cycle, a positive potential is supplied to the second movement bus 19, as a result of which the relay of the first

0 the actuator of the second switching unit, which becomes self-blocking, closes its contacts in the next relay circuit, polls the next control object, and so on. Similarly

5, polling by choice is also carried out from other switching units containing trigger elements.

After all control objects have been polled (regardless of the start mode), the reset button 45 is pressed, resulting in the device being prepared for the next cycle of operation.

Claims (1)

Claims 5 An apparatus for interrogating control objects, comprising a control point, a communication line consisting of a common bus, a motor bus, a direct start bus, a reverse start wire and successively connected switching blocks, each with the exception of the first, consists of serially connected start elements and actuators, the first switching unit contains serially connected actuators, the first inputs of the startup elements and the executive elements of the switching blocks are connected to the common bus of the communication line, the fourth inputs of the executive elements of the switching blocks, except for the first executive element of the first switching unit, and the fourth inputs of the startup elements of the switching unit are connected to the corresponding motor buses link, the third input of the first actuator of the first switching unit is connected to the first bus of the communication line, the control point contains the unit for starting and generating impulses of movement, the input of which is connected to my power source, and the output is connected to the common bus of the communication line, buttons the call, the first outputs of which are connected to the corresponding outputs of the first group of the starting block and the formation of motion impulses, the first and second groups of elements AND, the first and second elements OR, the outputs of which are connected to the inputs the first and second pulse shapers, respectively, the first and second amplifiers, a direct start button, the first output of which is connected to the first output of the first group of the starting and driving pulse unit, a reverse start button, the first output of which is connected to the third output of the first group of the starting and the formation of motion pulses, characterized in that, in order to increase the reliability and informational flexibility of the device by organizing a survey from any switching unit, at the control point of the introduction a third group of elements is AND, the third element OR, the third pulse shaper, the second output of the direct start button through the first booster and bus the direct start of the communication line is connected to the second input of the first actuator of the first switching unit, the second output of the reverse start button via the second amplifier and the reverse start line connection is connected to the fifth input of the last actuator of the last switching unit, the first inputs of the first and second groups of elements And are connected to the second pins of the odd and even call buttons, respectively, and the outputs are connected to the first and second inputs of the OR elements, respectively, the output of the third element OR is connected with the input of the third pulse shaper, and the outputs of the pulse shaper are connected to the corresponding bus lines of the communication line, the first and second inputs of the third group of elements And are connected to the corresponding the outputs of the second group of the start-up unit and the motion pulse generator, and the outputs are connected to the second inputs of the same elements AND of the first and second groups, the fifth inputs of the starting elements of the switching units are connected to the corresponding communication line buses.