JPH05297914A - Programmable controller - Google Patents

Abstract

PURPOSE:To provide a programmable controller which can prevent automatic control from malfunctioning even if a switch is operated by artificial mistake. CONSTITUTION:An MPU 1 writes a mask request flag in a RAM 3 when receiving a mask request command which is generated by a user M and makes the operation of an external hardware switch 5 ineffective through an external serial interface 6. Then the MPU 1 devices the flag in the RAM 3 when a process for reading the state of the switch of a system program in a ROM 2 is performed, and branches a process for reading the state of the external hardware switch 5, so that the process is not performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable controller used for various automatic controls including factory automation.

[0002]

2. Description of the Related Art Conventional programmable controllers are
Of the external hardware switches such as the mode switch for switching the operation mode, the initial switch, and the baud rate switch for the external serial interface, the switches that are considered to be infrequently used during normal operation are also scanned every time, and the switch status is read and processed. It was

[0003]

According to the processing method for reading each scan and switch state as in the above-mentioned conventional example,
If the switch is operated during artificial operation during normal operation, the automatic control may be erroneously operated. The present invention has been made in view of the above problems,
It is an object of the invention to provide a programmable controller capable of preventing a malfunction of automatic control even if a switch is operated by a human error.

[0004]

In order to achieve the above object, the present invention provides a programmable controller having an external hard switch such as a mode changeover switch for test mode or the like, an initial switch, a baud rate changeover switch for an external serial interface, or the like. In, in the mask request command to disable the operation of the external hard switch,
A means for controlling the signal processing of the external hard switch based on the mask invalid command for canceling the invalid state is provided.

[0005]

According to the configuration of the present invention, when the user gives a mask request command for invalidating the operation of the external hard switch which is considered to be infrequently used, the external hard switch is erroneously operated during the steady operation. Also, since the operation of the switch is invalidated, it is possible to prevent the automatic control from malfunctioning due to the switch operation due to a human error. Further, when the mask invalid command is given, the operation of the external hard switch is validated, so that the setting of the valid or invalid of the operation of the external hard switch can be easily performed by giving the command.

[0006]

EXAMPLES The present invention will be described below with reference to examples. Figure 1
Shows the basic configuration of the programmable controller used in the present embodiment, which is mainly the MPU 1 and the ROM 2 in which the system program is written and the RAM for storing data and the like.
3, an I / O bus 4, a port for reading the state of the external hard switch 5, an external serial interface 6 for exchanging commands and responses with the user M, and the like. As the external hardware switch 5, a mode changeover switch such as a test mode, a ROM operation changeover switch,
There are a baud rate changeover switch and an initial switch of the external serial interface 6.

In this embodiment, the MPU 1 is shown in FIGS.
The command processing and switch processing functions shown in FIG. 3 are provided, and these functions perform mask processing and mask removal processing for invalidating or enabling the operation of the external hard switch 5. Next, the operation of this embodiment will be described with reference to FIG. First, as shown in FIG. 2A, the MPU 1 receives a mask request command for invalidating the operation of the external hard switch 5 issued by the user M from the external serial interface 6 in the programming unit or the like.
Writes the mask request flag in the RAM 3. Then, as shown in FIG. 2B, when the process of reading the switch state of the system program in the ROM 2 is executed,
MPU1 does not correspond to valid / invalid setting. After reading the state of the execution-program creation changeover switch, etc., the flag in RAM3 is discriminated, and if the mask request flag is set, the state of the external hard switch is set. The process of reading is divided into no process. If the mask request flag is reset, the reading process of the external hard switch 5 is executed. When performing the mask release, the user M may issue the mask release command as in the case of the mask request command, and the MPU 1 receiving the mask release command resets the mask request flag in the RAM 3.

[0008]

The present invention is provided with means for controlling the signal processing of the external hard switch based on the mask request command for invalidating the operation of the external hard switch and the mask invalid command for canceling the invalid state. It is possible to invalidate the operation of the external hard switch even if the external hard switch is mistakenly operated during steady operation by only giving a mask request command to invalidate the operation of the external hard switch, which seems to be infrequent. Therefore, it is possible to prevent malfunctions in automatic control, improve safety, and because it is a soft process, there is an effect that the cost of system hardware does not rise. Since it is possible to enable the operation of the external hard switch that was disabled when given, Department effective operation of the hard switch, there is an effect that can be performed only by a simple operation of giving an invalid set up each of the command of.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a flowchart of each processing function of the same.

[Explanation of symbols] 1 MPU 2 ROM 3 RAM 5 External hard switch 6 External serial interface M user

Claims (1)

[Claims] 1. A programmable controller provided with an external hard switch such as a mode changeover switch for test mode or the like, an initial switch, or a baud rate changeover switch for an external serial interface, and a mask request command for invalidating the operation of the external hard switch and an invalidation. A programmable controller comprising means for controlling signal processing of an external hard switch based on a mask invalidation command for releasing a state.