JPS6295607A - Programmable controller - Google Patents

Abstract

PURPOSE:To reduce the labor and time needed for the tests and adjustment by controlling the feed and cut-off of power of an output power supply unit with the output of a switch and the output of an AND circuit that secures an AND with the system normal signal. CONSTITUTION:A system switch 67 and an AND circuit 68 are provided to a system monitor part 6 and the outputs of monitor circuits 61-63 are led to the circuit 68. Then the output of the circuit 68 is supplied to a switch 51 as a power supply make/break signal 69. A power supply unit 4, a central arithmetic processor 1 and an output power supply unit 5 are working normally and the system normal signal is delivered with the switch 67 turned on. Under such conditions, the switch 51 is closed and the control signal is supplied to a process from an output device 3. While the feed is cut off to the device 3 from the unit 5 if the switch 67 is turned off despite a system normal state where the circuits 61-63 are all delivering the normal signals.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to electrical connection/disconnection means for an output power source of a programmable controller.

[Conventional technology]

FIG. 2 is a block diagram showing a schematic configuration of a conventional programmable controller. In the figure, reference numeral 1 denotes a central processing unit that takes in input information from a process (not shown), processes it according to a program, and sends the results of the calculation process to the memory/relay drive circuit 31 of the output device 3 through a bus 2. supply 32 is an output relay controlled by this memory relay drive circuit 31,
The contact output of the contact 33 is sent as a control signal to the above process (not shown). 4 is a power supply device serving as a power supply for circuit operation (HC power supply) of the central processing unit 1, output device 3, and system monitoring unit 6; 5 is an output relay 3 of the output device 3;
This is a power supply device that serves as an output power source for driving 2.

The system monitoring unit 6 is a monitoring circuit 61 that monitors the power supply device 4.
, has a monitoring circuit 62 that monitors the central processing unit l, and a monitoring circuit 63 that monitors the output of the power supply device 5, and when each monitored unit is normal, for example,
(2) Generate a normal signal of the level and send it to the AND circuit 64. The AND circuit 64 includes each of the above-mentioned monitoring circuits 61, 62 and 6.
If the output of 3 is a normal signal at level 1, a system normal signal is sent, and if it is at level 1, a system abnormal signal is sent out. This system normal/abnormal signal 65 is used to display the system status. In addition to being sent to the external circuit, it is also supplied to the switch 51 as a power on/off signal 66.

[Problem that the invention seeks to solve]

By the way, conventionally, controller program tests and on-site adjustment tests are performed by stopping the sending of control signals to the process, that is, by turning off the output power supply device 5; In addition, in the conventional controller described above, the output power supply device 5 is electrically connected to the output device 3 when each predetermined part is normal. There were problems such as system abnormalities occurring when the system was turned off, and testing and adjustment required time and effort.

This invention was made to solve the above-mentioned conventional problems, and aims to provide a programmable controller that can reduce the effort and time required for testing and adjustment compared to the conventional one.

[Means to solve the problem]

In order to achieve the above object, the present invention adds a switch and an AND circuit to the system monitoring section to take a logical product of the output of the switch and the above system normal signal, and the output of the AND circuit is used to control the above output. The configuration is such that power supply/cutoff of the power supply device to the output device is controlled.

[Effect]

In this invention, by turning off the switch, only the output power supply device can be turned off without affecting other parts while the central processing unit is kept operating.

[Embodiments of the invention]

FIG. 1 shows an embodiment of the present invention, in which the system monitoring section 6 includes a system switch (manual switch) 67,
The outputs of the monitoring circuits 61, 62 and 63 are led to the AND circuit 68, and the output of the AND circuit 68 is used as a power on/off signal 69 to send to the switch 51.
It differs from the conventional case shown in FIG. 2 in that it is supplied with

In this configuration, when the power supply device 4 for circuit operation, the central processing unit 1, and the power supply device 5 for output are normal,
That is, when the system normal signal is output and the system switch 67 is turned on (ON), the switch 51 is closed, so a control signal is supplied from the output device 3 to a process (not shown). System switch 67 is OFF
Then, even if the system is in a normal state where all the monitoring circuits 61 to 63 are generating normal signals, the output power supply 5
The power supply to the output device 3 is cut off.

In this way, even if the system switch 67 is turned off, the system normal/abnormal signal 65 is generated normally.
When performing the above-mentioned program test, etc., it is possible to perform this while maintaining the system in normal operation.

In the above embodiment, the output method of the output device 3 is a relay drive, but the same effect can be obtained even if other drive methods are used.

〔Effect of the invention〕

As explained above, this invention allows tests and adjustments such as program tests to be carried out by simply turning off the system switch and in the normal state of the system, reducing the time and effort required for the above tests and adjustments. can be reduced compared to

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional programmable controller. In the figure, 1- central processing unit, 3- output device,
5 - Output power supply device, 6 - System monitoring section, 61 -
63-monitoring circuit, 64.68-AND circuit, 67--switch. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] A programmable controller has a central processing unit that takes in input information from a process and processes it according to a program, and an output device that creates a control output according to the calculation result of the central processing unit and sends it to the process. A system monitoring unit that monitors the status of the system and sends out a system normal signal when these are normal, and an output power supply device that is electrically connected to the output device to create the control output based on the system normal signal. In the case where the system monitoring unit is connected, the system monitoring unit has a switch and an AND circuit that takes a logical product of the output of the switch and the system normal signal, and the output of the output power supply device is controlled by the output of the AND circuit. A programmable controller characterized in that electrical connection/disconnection to a device is controlled.