DD299991A5 - Method for connecting a programmable control device with operating and / or display elements and circuit arrangement for a programmable control device - Google Patents

Abstract

A memory-programmable control device (2) is connected via serial data lines (8a, 8b) to an allocated operating and display device (9). The parallel output lines (25) of the memory device (2) are connected to a register (24), from which the data records intended to control the display elements (12) are read out in series and forwarded to the display device (9b). The control signals supplied from the operating elements (11) are fed as serial data records to an input shift register (16), the memory contents of which are entered cyclically and in parallel via connections into a result register (21), the output lines (23) of which are connected in parallel to the inputs of the control device (2). <IMAGE>

Description

For this 3 pages drawings

In building services, especially in larger buildings such. As hospitals are at different and usually far away from each other places a variety of field devices, d. H. electrical consumers installed. This may be e.g. to act actuators, fan motors, lighting equipment and the like. The leads of this Feldgeräta are usually combined at a central location in the building in cabinets and fed there by appropriate control devices, which may also be part of a control loop.

The control of the field devices corresponding to the respective control output of a control device usually takes place conventionally via relays, auxiliary contactors and coupling relays.

To operate the control devices is at least one operating device, such. As a control panel, provided with a plurality of control elements such as switches. In addition, a plurality of display elements is usually required, with which the switching state of field devices, parameters of the control device and other Informptionsen

can be displayed. For the electrical functional sequence, it is necessary that each of the operating elements (control switch, push button) and the display elements (signal lights) is connected via a plurality of electrical connection lines with the control device.

Through the use of programmable logic controllers ("PLC") Although the effort especially in the control units (auxiliary contactors, relays, mechanical counters, time relays, flasher relays and the like) can be reduced, but this is the wiring problem in the range between control elements or display The more powerful the control device, the larger and more varied the need for control elements and display elements For each of these elements, a separate, ie parallel, input and a parallel input must be present at the control device (PLC) This results in a high cost of wiring display and controls, complicates subsequent modifications to the circuitry, and also prevents control and display elements from being physically separate from the controller thereby the Verd.ahtungsau fwand goes up in the immeasurable.

The object of the invention is to avoid the disadvantages of the known, in particular to provide a method and a circuit arrangement for a programmable control device, by the optimally simple manner and with low circuit complexity and space requirement, the functional connection of the control device (PLC) and operating or display elements can be produced.

According to the invention, this is achieved primarily with a method according to claim 1 or a circuit arrangement according to claim 3.

Instead of the conventional switch and display elements with direct galvanic connection to the control device, the invention thus selects a method or a circuit arrangement in which the state of the operating elements is polled cyclically and the ascertained information is cyclically read into signal groups in a shift register. Upon completion of such a cycle, the state of each individual memory of the shift register corresponds to the state of the associated control element so that the signals can be transferred in parallel from the individual memories to a corresponding number of memory locations after being read in a second cycle. The outputs of the memory locations of the result register are the input side to the parallel control inputs of the programmable controller, so that there is constantly present at each input a signal which egg state corresponds to an associated control element. By ongoing transmission of such signal groups and cycle repetition can orsiahtlicherweiso always update the state of the result register such that the PLC is driven on the input side according to the position of the control elements. Cycle times of e.g. 5ms to 10ms proven. Depending on the number of operating elements and according to the required transmission speed can be provided as many shift registers, each of which represents a certain number or a specific group of operating elements. In this way, both the circuit complexity in the operating device and the number of connecting cables between the PLC and operating device or display device is drastically reduced. Shift registers and result registers can be designed as accessories for conventional PLCs and connected to their parallel inputs. Alternatively, it is of course also possible to make the conversion of the signals in a suitably designed PLC itself.

Likewise, the invention provides for serially transmitting the output signals of the PLC for the display elements and converting them into corresponding registers. For clocked transmission and reading the signals, a clock is to be provided, wherein a clock line is provided for synchronization of the transmission between the display device or operating device and PLC. It is expedient if the operating and display device has separate memory for the operating elements and the display elements

 The invention is explained in more detail below in an embodiment with reference to the drawings. Show it

Fig. 1: the schematic representation of a switchgear with a control device and an operating and display device.

2 shows the schematic representation of the interconnection of an operating and display device with a control device having the features of the invention,

Fig. 3 is a block diagram showing the input shift register and the result register, and Fig. 4 is a block diagram showing the output register.

According to figure '. is in a control cabinet 1, not shown, a programmable logic controller 2 (PLC) is provided. The SPS controls in a known manner a number of power contactors 4, which are connected via a terminal block 5 with consumers, not shown, such as ventilation motors, lighting equipment and the like. Motor protection switches 3 are provided as protective devices for motors. Fuses 6 are provided to protect the various circuits.

The PLC 5 controls in a programmable manner the various connected to the terminal block 5 consumer or field devices. 7

On the input side, the PLC is connected via a connection line 8 (data bus) with a combined operating and display device 9. The operating and display device 9 is arranged in the door 10 of a Schaltüchrankes, as indicated schematically in Figure 1. In addition, a remote control panel 9a may be provided. As can be seen from the schematic illustration in FIG. 2, the operating and display device 9 consists of a plurality of operating devices 9a and display devices 9b. Each of the operating devices 9a, in the embodiment 8 illuminated pushbutton 11 as control elements. Each of the illuminated pushbuttons 11 can be assigned a specific function of the PLC 2 or a function of one of the field devices 7. The number of illuminated push buttons 11 per operating device 9 a and the number of indicator lights 12 per display device (9 b) depends on the complexity of the system and the functions that the PLC 2 should perform. Of course, instead of the illuminated pushbutton 11, any other switching elements can be used.

Each of the display devices 9b has, according to FIG. 2, sixteen indicator lamps 12 as display elements. The indicator lights 12 may each be assigned to a specific operating state of the PLC or the field devices 7. The operating devices 9a and the display devices 9b are connected by means of a bus board, not shown, with a system card 13, which has an interface 14 for connecting the line 8. The line 8 has eight wires, wherein one of the wires is a clock line with which the clock frequency of the PLC with the clock frequency of the operating and display device synchronizing ν 'd.

As shown schematically in FIG. 3, sixty-four illuminated pushbuttons 11 are each connected to an arrangement 15, in which signals are stored that correspond to the respective position of one of the illuminated pushbuttons 11. In the frequency of the clock synchronized on the line E0 between the array 15 and an input shift register 16, in a polling cycle on a line Qa, all information stored in the array 15 and an instantaneous value of the data are serially transmitted Illuminated pushbutton 11 correspond. The input shift register 16 is fed with data via an input 17. As indicated, the input shift register 16 has sixty-four memory locations C1 to C64. The data applied through the input 17 are "shifted" to the shift register 16 in time with the clock line £ 0 until a data group of sixty-four pieces of information corresponding to the switch positions of sixty-four Illuminated push-button 11 - is in the shift register 16. The data line 8a is an additional line to the labeled with EO to E 5 wires connecting the interface 14 with the PLC 2 (Figure 2) .Each of the wires can analogous to Figure 3, an arrangement 15 with connect an input shift register 16, so that in each case the information of sixty-four Bedieniingselementen are read into the memory locations of an input shift register 16 via a data line.

As shown schematically in Figure 3, the lines E1 to E5 are also connected to an evaluation logic 18, which is also connected to the clock line EO. The evaluation logic 18 determines the beginning and the end of the transmission of data groups on Jer line 8 a. Once all sixty-eight information has been read into the input shift register 16, the evaluation logic 18 determines the end of a transmission cycle. Via a control line 19, the input 20 of a result register 21 is driven, which now parallel assumes the pending at the memory locations C1 to C64 of the input shift register 16 information about parallel connection lines 22. In the result register 21, the acquired information, which correspond to the switching positions of the illuminated pushbutton 11, remain standing. They are connected to the input of the PLC 2 via output lead 23. At the same time, a new transfer of a group of sixty-four pieces of information over the data line 8a and the input 17 to the input shift register 16 begins. During the time of transfer, the result register 21 stores the information of the previous cycle. Only when the shift register 16 has taken over again a complete group of sixty-four information during the subsequent cycle, the evaluation register 18, the result register 21 is driven again, and the new record is taken over the connection 22 in parallel. Due to the high clock frequency on the clock line EO cycle time is only a few ms, so that the result register 21 is supplied in very short time intervals each with current state information and present at the input of the PLC with a negligible delay current switching data. Of course, the number of memory locations in the input shift register 16 can be increased or decreased depending on the requirements of the Gasamtanordnung, and also the number of data lines can be adapted to the requirements of a system. The query of the illuminated pushbutton 11, the caching of the information and reading out into the data line 8a is controlled in a known manner by a microprocessor and requires no further explanation. It is only important that via the clock line EO, the arrangement 15 and the input shift register 16 and the result register 21 are synchronized so that a proper assignment of the data to each illuminated pushbutton 11 and a corresponding "filing" in one of the memory locations of the input 4 shows an output shift register 24 located at the outputs of the PLC 2 which drive the indicator lights 12. In conventional systems, each of the output lines 25 is connected to one of the indicator lights 12, while in the present case the output lines 25 are located at the inputs of the memory locations of the shift register 24. Analogous to the transmission cycles to the input shift registers 16 and the result register 20 in Figure 3, the output shift register 24 is driven via a clock line EO and a control line 26 from a control circuit, not shown same transfer cycle of 5 As in the input shift register 16, the output shift register 24 is interrogated, and the signals appearing on the lines 25 are converted into serial data groups, which are sent via a data line 8b to an array 27 in which the incoming data is applied to the individual indicators 12 be assigned and stored. The transmission with short cycle times ensures that the switching state of the indicator 12 coincides virtually instantaneously with the output from the PLC to the output lines 25 signals. The conversion of the signals arriving via the data line 8b in parallel for the control of the indicator lights 12 available signals is preferably done in the arrangement 27 analogous to the operation of input shift register 16 and result register 21. As in dashed lines in Figures 2,3 and 4 is indicated, the elements required for the data conversion, namely the evaluation logic 18, input shift register 16, result register 21 and output shift register 24, summarized in a schematically indicated input part 2 a, which is part dor SPS 2. Of course, it is also conceivable to implement the input part 2a as an independent device with its own power supply, etc., and to establish a connection by means of the output lines 23 and 25 to the corresponding outputs or inputs of a conventional PLC.

Claims (6)

A method for operatively connecting an electronic, provided with a data storage, programmable control device (2) for home automation with a plurality of control elements (11) and / or display elements (12), characterized in that the of the Bedienungs Element (11) signals are queried and read serially in signal groups via at least one line (8a) in a first cycle in a provided with individual memories shift register (16) that after reading in a second cycle, the signals in parallel from the individual Memory locations of the shift register (16) in a result register (21) are transmitted with a corresponding number of memory locations, and that the control inputs of the programmable controller (2) by the outputs (23) of the memory locations of the result register (21) are driven. 2. The method according to claim 1, characterized in that the output signals of the programmable controller (2) in parallel to the inputs (25) of a provided with a plurality of memory locations shift register (24) are placed, and in that the shift register (24) information stored cyclically passed as a serial data set to an arrangement (16) for driving the display elements (12). 3. Circuit arrangement for a programmable control device (2) for the building management of Foldgeräten (7) with at least one display device (9 b) for displaying a plurality of operating conditions and at least one operating means (9 a) for performing a plurality operating operations, wherein the control device has parallel operating inputs (23) and display outputs (25) for connection to operating elements (11) of the operating device (9a) or to display elements (12) of the display device (9b), characterized in that the inputs (23) and the outputs (25) each comprise at least one arrangement (16,21,24) for converting serial input data into parallel input data for the inputs (23) or for converting parallel output data at the outputs (25) are connected in serial data groups. 4. Circuit arrangement according to claim 3, characterized in that the inputs (23) of the control device (2) are connected in parallel with the outputs of a result register (21) that the memory locations of the result register are connected in parallel with the memory locations of a shift register (16), in that the serial input (17) of the input shift register (16) is connected to the output of the operating and display device (9) via a data line (8a), and in that evaluation logic (18) for cyclically actuating the result register (21 ) Is connected to this in such a way that in each case after the serial read in of a data set in the input shift register (16), the data are taken in parallel in the result register (21). 5. A circuit arrangement according to claim 3 or4, characterized in that the output signals of the control device (2) to the parallel inputs of an output shift register (24) are placed, and that the serial output of the shift register (24) via a data line (8 b) with the operating and display device (9) is connected. 6. Circuit arrangement according to one of claims 3 to 5, characterized in that the shift register (16, .24), the result register (21) and the evaluation logic (18) in an input circuit (2a) are combined, which is part of the control device (2 ).