JPS63254285A - Solenoid valve control method - Google Patents

Abstract

PURPOSE:To arrange so as to shorten a transmission time by making a control signal transmitted to a solenoid valve drive device a series signal in which an address previously fixed for every solenoid valve to be controlled is shortened through symbolization and a state signal is added to this. CONSTITUTION:If there is a change of states in either of the control signals 11 in parallel which are emitted from a parent control machine, an address matching a solenoid valve which has been commanded a conversion of states is generated by means of a parallel signal at an address signal generating circuit 2, and together with its address signal 12, a commanded new state is outputted by means of a state signal 13. This address signal 12 and the state signal 13 are arranged in series by means of a parallel-series conversion circuit 3 and sent to a control signal device sending-out circuit 5. This movement is conducted by the clock of the output of a movement clock generating circuit 4, and is to be outputted from the parallel-series conversion circuit 3 only right after the change of states having been commanded.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a solenoid valve control method that uses a plurality of solenoid valves to control fluid direction switching, and in particular to a method for transmitting control signals in a short period of time. The present invention relates to a solenoid valve control method for controlling a large number of solenoid valves that require controlling a solenoid valve drive device.

(Prior Art) Generally, solenoid valves are used to control the operation of automatic working machines in automobile production equipment, semiconductor manufacturing and inspection equipment, etc., and the solenoid valves direct the direction of working fluid to actuators such as air cylinders. Switching control is being performed. In that case, a large number of solenoid valves are used, and these many solenoid valves are arranged in groups, for example several to several dozen, combined in manifold piping. By configuring the solenoid valve manifold as an integrated unit with back piping, installation space can be saved. In order to control the opening and closing of such a solenoid valve manifold, a control device such as a sequencer or microcomputer is installed in a separate control panel or control box to control the opening and closing of the solenoid valve. It is connected to the control device by an extremely large number of electrical wires, that is, at least one more than the number of solenoid valves. For this electrical wiring, electrical cables are usually laid using duct wiring or piping.

Normally, as a means of transmitting multiple solenoid valve control signals via a single signal line via these cables, the solenoid valve control signals at a certain point in time are collected as a time-division serial signal, regardless of state changes. There are many cases where data is transmitted repeatedly over a fixed period of time.

Note that there are control devices that send out control signals only when the command status changes, but even in that case, the control signals that are sent to the transmission line are status signals that correspond to all of the solenoid valves and are serially transmitted in a time-sharing manner. It is sent in a lined signal format.

(Problem to be Solved by the Invention) In general, the electromagnetic manifold described above is normally used in one place from several to several dozen sets, so the number of status signals that control it is also several. The number can range from ten to several hundred. However, in the above-mentioned conventional solenoid valve control method, as shown in Fig. 3(a) and (bl), all the status signals are serially arranged in a time-sharing manner to form the control signal, so the time required for one transmission is long. Therefore, when the command status changes in an extremely short period of time, there is a delay in transmitting subsequent commands, and since signals with no status change are also transmitted, malfunctions are likely to occur if the transmission path is in poor condition. In addition, when wiring for control signal transmission is omitted and the control signal is superimposed on the power line and transmitted, power line transmission superimposes the signal by changing the power supply voltage waveform in some way, so If the control signal sent at one time becomes longer, there is a problem in that the influence of fluctuations in power supply voltage due to superimposition of control signals on the receiving side cannot be ignored.

The purpose of the present invention is to solve these problems, to reduce the length of the control signal sent at one time, to eliminate delays in solenoid valve control, and to reduce the power supply voltage even when the control signal is transmitted by power line. The purpose of the present invention is to provide a solenoid valve control method that has almost no effect on the

(Means for Solving the Problems) In order to achieve the above object, a solenoid valve control system according to the present invention includes a solenoid valve drive device 20 that controls fluid, a control device 10 that controls the solenoid valve drive device 20, and a solenoid valve drive device 20 that controls fluid. , a transmission line 30 connected between the control device 10 and the electromagnetic valve driving device 20 to transmit control signals, and controlled by the control device 10 based on control signals from the parent controller 1 that generates control signals. an address signal generation circuit 2 that outputs an address signal encoded with an address given in advance to a solenoid valve to be used and a status signal indicating a command status; and an address signal generation circuit 2
a parallel-to-serial conversion circuit 3 that converts the parallel signal output from the output into a serial signal; and an operation clock generation circuit 4 that generates a clock pulse when receiving a transmission start signal from the parent control IJNI and causes the parallel-to-serial conversion circuit 3 to perform conversion. and a control signal receiving circuit 21 that includes a control signal sending circuit 5 that receives the control signal from the parallel-to-serial converter circuit 3 and sends it to the transmission line 30, and that extracts the control signal from the transmission line 3o to the electromagnetic valve driving device 20. A serial/parallel conversion circuit 22 that converts the serial signal output from the control signal reception circuit 21 into a parallel signal, a code conversion circuit 23 that decodes the address signal output from the serial/parallel conversion circuit 22, and a code conversion circuit 23 that decodes the output of the serial/parallel conversion circuit 22. A transmission end detection circuit 24 that detects from the output that transmission of the control signal has ended, and a plurality of latch circuits that hold status signals from the series/parallel circuit 22 based on the outputs of the code conversion circuit 23 and the transmission end detection circuit 24. 27a, a logic circuit 25 including 27b-21x,
A solenoid valve 28 controlled by latch circuits 27a, 27b, . . . 27x is provided, and the control signal is transmitted when it is necessary to change the state of the solenoid valve to be controlled.

(Example) Next, an example of a solenoid valve control system of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the electromagnetic valve control method according to the present invention.

As shown in FIG. 1, the control device 1o includes an address signal generation circuit 2 that receives a control signal from a master controller 1 and outputs an encoded address signal and a status signal indicating a command status, and a parallel signal generator The parallel-to-serial conversion circuit 3 converts the address signal and status signal into serial signals, and the clock for controlling the operation of the parallel-to-serial conversion circuit 3 is transmitted from the parent controller 1 fB.
4, and a control signal sending circuit 5 that sends the output of the parallel-to-serial conversion circuit 3 to the transmission line 3o.

The solenoid valve driving device 2o also includes a control signal receiving circuit 21 that receives and extracts control signals from the transmission line 3o, a serial-to-parallel conversion circuit 22 that converts the extracted serial control signals into parallel signals, and a serial-to-parallel conversion circuit 22. The code conversion circuit 23 decodes the address pulse of the output and outputs the presence or absence of a state change for each location to be controlled, and the control signal is received from the control signal circuit 21, and the stop pulse sent at the end of the signal is used. A transmission end detection circuit 24 that detects the end of transmission, and gate groups 26a and 2 that open the gates when a stop pulse is received and allow the output of the code conversion circuit Iil & 23 to pass through.
6b...26X and a latch circuit group 27a, 27b... that holds the status signal of the output of the serial/parallel conversion circuit 22 in the latch circuit corresponding to the electromagnetic valve that receives the status command from the output of the code conversion circuit 23. Logic circuit 2 including 27X
5, and a solenoid valve manifold 28 having solenoid valves controlled by the outputs of latch circuits 27a, 27b, . . . 27x.

Therefore, the parallel control signal 11 issued from the parent controller
If there is a state change in any of the above, the address signal generation circuit generates an address corresponding to the solenoid valve commanded to change the state as a parallel signal, and outputs the new state commanded as the state signal 13 along with the address signal 12. do. The address signal 12 and status signal 13 are arranged in series by the parallel-to-serial conversion circuit 3 as shown in FIG. 2(a) or (bl) and sent to the control signal device sending circuit 5. Since the clock is output from the operation clock generation circuit 4, which is activated by the transmission start signal 14 issued as a transmission command, the signal is output from the parallel-to-serial conversion circuit 3 only immediately after the state change is commanded. As shown in FIG. 2, a star I pulse indicating the start of transmission is placed before the address signal (address pulse), and a stop pulse indicating the end of transmission is added after the status signal pulse. The control signal sending circuit 5 receives the control signal having such a waveform, converts it so that the signal can be carried on a power line or an optical cable, and sends it out to the transmission line 3o.

Next, the serial control signal received by the control signal receiving circuit 21 of the electromagnetic valve driving device 2o is output as a state signal 31 and an address signal 32 as parallel signals by the serial/parallel conversion circuit 22. Since this address signal 32 is encoded, it is decoded by the code conversion circuit (] O) so that it can be determined for each solenoid valve which solenoid valve the sent status signal commands to change the status. , output corresponding to each solenoid valve. On the other hand, the transmission end detection circuit 24 detects that the control signal sent from the output of the control signal receiving circuit 21 has ended, and sends out a stop pulse 33. Gate circuits 26a, 26b・
...26x, the gate is opened by the stop pulse 33 and the output of the code conversion circuit 23 is transferred to the latch circuits 27a and 27.
b...Input to 27x. Latch times [2 & 27a, 2
7b...27x, only the latch circuit that receives the input from the code conversion circuit 23 takes in and holds the state signal 31 from the serial/parallel conversion circuit 22. In this way, information on the status signal when a status change command is issued is held in each of the latch circuits, and each solenoid valve of the solenoid valve manifold 28 is controlled according to this held status. For example, assuming that there are 16 addresses, numbered 0 to 15, set for each solenoid valve on the second day of the solenoid valve manifold, the operation of the 15th solenoid valve.

When controlling non-operation, when operating,
), and to make it inactive, send a signal like +bl in Figure 2. Here, the pulse 88 means a weight of 8 in the binary number of the address, the pulse A4 means a weight of 4, the pulse A2 means a weight of 2, and the pulse A1 means a weight of 1.

Therefore, in order to transmit the same operation using a conventional control signal, control signals having the waveforms shown in FIGS. 3(a) and (11) must be sent. In this way, although 16 pulses must be sent in the conventional method, only 7 pulses are required in this embodiment.

If the number of solenoid valves to be controlled exceeds 32, the difference becomes even larger. Therefore, even if a control signal is sent immediately for each status change command using the conventional method, the transmission of the previous control signal and the subsequent control signal cannot be overlapped, so there is a delay in the transmission of the subsequent control signal. There is a high possibility that this will occur.

In contrast, in this embodiment, the control signal is extremely short, so there is very little possibility of this happening. Furthermore, if a power line is used for the transmission path, the control signal is transmitted by changing the voltage waveform, regardless of whether the power source is DC or AC, and the control signal is separated on the solenoid valve drive side and the solenoid valve The power supply used for control smoothes the power supply voltage and is used as a power supply for each city, so the longer the control signal superimposed on the power supply, the more the influence of power supply voltage fluctuations on each part of the solenoid valve control device cannot be ignored. In this respect as well, it is better if the control signal can be sent in a short time as in this embodiment.

(Effects of the Invention) As explained in detail above, the present invention shortens the control signal transmitted from the control device to the solenoid valve drive device by encoding a predetermined address for each solenoid valve to be controlled. By making it a serial signal with a status signal,
This has the effect that the transmission time for one transmission can be significantly shortened compared to the conventional method.

Therefore, if this embodiment is used, there is less risk of delay in controlling the solenoid valve, and when transmitting a control signal superimposed on the power line that supplies power from the control device to the solenoid valve drive device, This has effects such as being able to reduce changes in the voltage of the power supply supplied to the electromagnetic valve drive device.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of a solenoid valve control system according to the present invention. FIG. 2 is a waveform diagram showing a configuration example of a control signal transmitted by the embodiment of FIG. 1. FIG. 3 is a waveform diagram showing an example of the structure of a control signal transmitted by a conventional electromagnetic valve control method. 1... Parent controller 2... Address signal generation circuit 3... Parallel/serial conversion circuit 4... Operation clock generation circuit 5... Control signal sending circuit 10... Control device 20... Electromagnetic Valve driving device 21...Control signal receiving circuit 22...Serial to parallel conversion circuit 23...Code conversion circuit 24...Transmission end detection circuit 25...Logic circuit 28...Solenoid valve manifold 30...・Transmission line

Claims (4)

[Claims] (1) Consisting of a solenoid valve drive device that controls fluid, a control device that controls the solenoid valve drive device, and a transmission line that is connected between the control device and the solenoid valve drive device and transmits a control signal, an address signal generation circuit that outputs an address signal encoded with an address given in advance to a solenoid valve to be controlled based on a control signal from a parent controller that generates a control signal to the control device, and a status signal indicating a command status; a parallel-to-serial conversion circuit that converts the parallel signal output from the address signal generation circuit into a serial signal; and a parallel-to-serial conversion circuit that generates a clock pulse when receiving a transmission start signal from the parent controller and converts the parallel signal to a serial signal. a control signal receiving circuit for extracting the control signal from the transmission path to the electromagnetic valve driving device; a serial-parallel conversion circuit that converts a serial signal output from the control signal receiving circuit into a parallel signal; a code conversion circuit that decodes an address signal among the outputs of the serial-parallel conversion circuit; and an output of the control signal receiving circuit. a transmission end detection circuit for detecting the end of transmission of a control signal from the serial-parallel circuit, and a plurality of latch circuits for holding status signals from the series-parallel circuit based on the outputs of the code conversion circuit and the transmission end detection circuit. An electromagnetic device comprising a logic circuit and a plurality of electromagnetic valves controlled by the output of the latch circuit, and configured to transmit the control signal when it is necessary to change the state of the electromagnetic valve to be controlled. Valve control method. (2) The solenoid valve control system according to claim 1, wherein the solenoid valve is a solenoid valve of a solenoid valve manifold formed by collecting a plurality of solenoid valves. (3) A power line of a power source common to the control device and the electromagnetic valve driving device is used in the transmission path, and the control signal sending circuit is a circuit that superimposes a control signal on the power source and sends it out, and 3. The electromagnetic valve control system according to claim 1, wherein the signal receiving circuit is a circuit that separates and extracts the control signal from the power supply line. (4) Claim 1 or 2, wherein an optical cable is used for the transmission path, the control signal sending circuit includes an electrical-to-optical conversion circuit, and the control signal receiving circuit includes an optical-to-electrical conversion circuit. The solenoid valve control method described.