JPS5972503A - Sequence controller - Google Patents

Abstract

PURPOSE:To continue the original sequence control after a power supply is recovered in case the power supply has been down due to an instantaneous stop of an AC power supply during working of a machine by resetting a microprocessor to prevent the runaway of relating devices. CONSTITUTION:A sensor 1in supplied from each part of a machine is fed to a sensor input circuit 1, and the output of the circuit 1 is supplied to a microprocessor 2. The processor 2 senses and decides a signal 1in sent from the circuit 1 and delivers a signal to a driver 3 to actuate tha machine. Then the driver 3 delivers a driver signal 3 out to each part of the machine. Here if a power supply 42 has been down, the power supply is cut off to a processor 2. Thus the working of the processor 2 is stopped, and no output signal is delivered to the driver 3. Therefore it is impossible to actuate the machine. While the circuit 1 does not work if a power supply 41 has been down. At the same time, the processor 2 is stopped by a reset circuit 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a sequence control device that uses a microprocessor to control sequences of various devices.

2. Description of the Related Art In general, when controlling the sequence of a machine, it is necessary to perform complex control using complex electronic circuits such as various sensors and drivers, and various power sources with different voltages. With the recent development of microprocessors, it has become possible to have a microprocessor execute sequence control, thereby providing a small and inexpensive sequence control device. In such a sequence control device, if even one of the plurality of power supplies goes down, the device may malfunction and the sequence control may run out of control. In order to prevent this, conventional systems have added a circuit that turns off other power supplies that could cause a runaway if even one power supply goes down, or a circuit that turns off all driver circuits. It was necessary to take steps such as adding As a result, many expensive and complicated circuits must be used, which is a major obstacle to miniaturization and cost reduction of devices.

In addition, power outages can lead to long-term power outages due to damage to the power supply, etc.
There are two types of short-term interruptions caused by instantaneous interruptions of the C power supply, but it is particularly difficult to eliminate malfunctions caused by instantaneous interruptions of the power supply, and a complicated circuit is required.

Purpose The present invention has been proposed in view of the disadvantages of the conventional example described above, and its first purpose is to reset the microprocessor when the output voltage of any one of the plurality of power supplies goes down. The object of the present invention is to propose a sequence control device that prevents runaway sequence control. Another object of the present invention is to store a drop in any one output voltage, and to detect this by a microprocessor, thereby preventing a sequence control from running out of control due to a drop in output voltage. This is where we propose.

Description of Embodiments (First Embodiment) In FIG. 1, l is a sensor input circuit, 2 is a microprocessor, 3 is a driver, 4 is a power supply, 5 is a reset circuit, and 41 is a power supply supplied to the sensor input circuit 1. So, 1
1 is the voltage, 42 is the power supply to the microprocessor 2, 12 is the voltage, 43 is the power supply to the driver 3, and 13 is the voltage.

Sensor signals of 1 inch from various parts of the machine are input to a sensor input circuit 1, and its output is input to a microprocessor 2. The microprocessor 2 senses and judges the signal 1 in from the sensor input circuit 1 according to a specific program, and outputs a signal to the driver 3 to operate the machine. The driver 3 receives the signal and outputs a drive signal 3 out to each part of the machine. The drive section signal a out is, for example, a signal for driving a motor, a signal for lighting a rung, a signal for generating high voltage, etc. For example, power supply 4
When the microprocessor 2 goes down, the power supply to the microprocessor 2 is cut off and the microprocessor 2 stops, and there is no output signal to the driver 3, making it impossible to operate the machine. In this case, runaway of the machine does not occur. On the other hand, power supply 41
When the sensor input circuit 1 goes down, the sensor input circuit 1 becomes inoperable.

At this time, for example, if the reset circuit 5 is not present, the microprocessor 2 will not be able to respond to the motor drive signal issued to the driver 3, and will not receive a signal indicating that the motor is rotating. If the signal is sent to the driver 3, the motor will continue to rotate. This causes the machine to run out of control. However, the reset circuit 5 has the output voltage 11, 12.1 of each power supply 41.42.43.
3, if any one goes down, a reset signal 16 (''L# level) is generated to reset the microprocessor 2, so there is no output signal to the driver 3. There is no possibility that the drive mechanism may malfunction.

FIG. 3 is a detailed diagram of the reset circuit 5. 11 is the voltage for the sensor input circuit, 12 is the voltage for the microprocessor, and 13 is the voltage for the driver circuit, which correspond to the numbers in FIG. TRl-TR3 are NPN type transistors,
R1-R6 are resistors, and DI-D2 are diodes. For example, when the voltage 11 decreases, the pace potential of the transistor TRI decreases, so it is cut off, and current flows into the transistor TR2 through the resistor R2 and the diode DI, turning on the transistor TR2, and its output signal 16 becomes low.
” level, the microprocessor 2 shown in FIG. 1 is reset.Similarly, in FIG. TR2 is turned on and its output becomes L''. Therefore, the reset signal goes to 'L' level and resets the microprocessor 2 shown in Figure i1.
Stop the operation of equipment such as motors.

On the other hand, if the voltage 12 goes down, as already mentioned,
Further, since the power supply to the microprocessor 2 itself is cut off, no drive signal is generated to the driver 3, and runaway of the machine is prevented.

That is, even if the output voltages 11, 12, and 13 of any of the power supplies go down, runaway of the machine will not occur.

(Second Embodiment) The embodiment shown in FIG. 2 is similar to the reset circuit 5 in FIG.
A flip-flop circuit 6 is used for switching, and its output 1
4 is input to the microprocessor 2. Similar to FIG. 1, sensor signals from various parts of the machine are input to a sensor input circuit 1, whose output 14 is input to a microprocessor 2. microprocessor 2
senses and judges the 1-inch signal from the sensor input circuit 1 according to the program, and outputs a signal to the driver 3 to operate the machine. The driver 3 receives the signal and outputs a drive signal 3out to each part of the machine. The drive signal 3 out is, for example, a signal for driving a motor, a signal for lighting a lamp, or the like. Here, voltage 1
When 1 goes down, the flip-flop in the flip-flop circuit 6 is cleared, and its output signal 14 becomes @LH. The microprocessor 2 senses the output signal 14 and knows that the voltage 11 has dropped, and stops outputting the drive signal to the machine.

FIG. 4 is a detailed diagram of the flip-flop circuit 6, where Dl-D2 are diodes, R3-R4 are resistors, and TR2
is a transistor, which is the same as the circuit shown in FIG. 7
is a flip-flop, 14 is the output signal of the flip 70 block 7, and 15 is the output signal of the flip flop 70 from the microprocessor 2.
This is a preset signal to the Tsugu 7. Now, when the device is powered on, a signal 1 is sent from the microprocessor 2 as shown in FIG.
5 is output and resets the flip 70 knob 7 shown in FIG. 4, and the output signal 14 of the flip 70 knob 7 becomes "H". For example, if the voltage 11 shown in FIG. 2 is cut off at this point ζ,
As shown in FIG. 3, the transistor TR2 is turned on and the signal 16 becomes L" level. In FIG. 4, the output signal 16 of the transistor TR2 becomes t L H, so 7
Ritsuzo 70 Tuzo 7 is cleared and its output signal 14 is I
It becomes L% level. In FIG. 2, microprocessor 2 can sense output signal 14 and know that voltage 11 has been disconnected. Even when other power supplies go down, it can be considered in exactly the same way as the embodiment shown in FIG.

For example, when voltage 13 stops, output 16 of TR2
is not 1L", and it is decided to clear the 7 degree 70 knob 7. Therefore, a @L'" level signal will be output from the 7 degree 70 knob 7, and the microprocessor 2 will set the voltage 13. can tell when it's down. As a result, the microphone processor 2 controls the drive signal to the driver 3 to prevent the machine from running out of control according to the program stored therein. Further, even if the voltage 12 goes down, the microprocessor 2 will stop itself, as in the embodiment described in FIG. 1, so that subsequent runaway of the machine can be prevented.

Note that power is supplied to the flip 70 shown in FIG. 4 from the power source 42 shown in FIG. 2.

According to this embodiment, unlike the first embodiment, the microcomputer 2 is not reset when the voltage 11 or 13 goes down, so if the power supply 41 or 43 eventually returns, the power supply continues to be turned off. It is also possible to continue the sequence from before it went down. Therefore, the microprocessor 2 senses the output of the 7-lip-flop 7,
When the output signal 14 is at the "L" level, the shift flip 70 knob 7 is periodically preset by the preset signal 15. After executing the preset operation, sense the output signal 14 again, and if this signal level is ILI+ level, it means that the power supply has continued to be down, and if it goes to ``H# level, it means that the power supply has been stopped. I understand.

In the glue set circuits of FIGS. 3 and 4, the voltage is a positive potential, but it may also be a negative voltage, for example.

In that case, the transistors TRI and TR3 may be of PNP type, or the transistors may be omitted and photocouplers may be used. Further, the polarity of the output signal of the 7-lip-frog 6 may be positive logic or negative logic. Furthermore, there is no limit to the number of power supplies.

Effects As explained above, according to the present invention, A
By resetting the microprocessor in response to a power failure caused by an instantaneous stoppage of the C power supply, it is possible to prevent peripheral devices such as motors from running out of control.

In addition, by using a sensing method that stores power down in a state memory element and senses this state, the sequence control that has been performed so far can be temporarily interrupted, and once the power is restored, the original sequence control can be resumed. You can continue.

Furthermore, compared to the conventional method in which a circuit is installed on the stain source side to turn off other power supplies when one power supply goes down, the present invention has a simpler circuit configuration, and the cost of equipment implementing the present invention can be reduced. It can be done.

[Brief explanation of the drawing]

1 and 2 are block diagrams showing an embodiment of the present invention, FIG. 3 is a circuit diagram showing details of the reset circuit shown in FIG. 1, and FIG. 4 is a detailed circuit diagram of the 7-lip-flop circuit shown in FIG. 2. FIG. Here, 4...power supply

Claims (1)

[Scope of Claims] 1. A microprocessor that determines the state of the controlled object based on information from the sensor input circuit and outputs control information to the driver, and at least two or more power supplies that supply power to each load. and a detection circuit that monitors the output voltage of each of the power supplies and detects that the output voltage of at least one of the power supplies has decreased,
A sequence control device characterized in that the microprocessor is reset when one output voltage drops. 2. A microprocessor that determines the state of the controlled object based on information from the sensor input circuit and outputs control information to the driver, at least two or more power supplies that supply power to each load, and the output of each power supply. a detection circuit that monitors voltage and detects that the output voltage of at least one of the power supplies has decreased; and a state memory element whose output state changes depending on the output of the detection circuit; A sequence control device characterized in that the microprocessor recognizes the output state of the state storage element when one output voltage decreases.