JP2970141B2 - Sequence control device with recoverable fuse contact function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable controller and a sequence controller incorporated in a numerical controller.

[0002]

2. Description of the Related Art Conventionally, in order to execute an operation only once when a specific condition occurs, it has been realized using a sequence for self-holding or the like. FIG.
Is an example in which the function of the self-holding sequence is applied.
In a configuration in which a target process is executed when the relay output of B is established, the fact that the process has been executed once with the relay output of C is held. Since the B contact of the C relay acts on the B relay output with a logical product, the B relay output is established only once. Therefore, the target processing is executed only once. Further, since the B contact of the D relay acts on the C relay output by a logical product, when a return signal is input, the C relay output is not established and the holding operation is released.

FIG. 6 shows an example utilizing a jump instruction. Normally, the intermediate two processes are skipped without being executed by the jump instruction. When the jump command is not satisfied, the target processing is executed, the relay output of B is also satisfied,
It holds that the process has been executed once. Since the contact point of B acts on the logical sum of the input signal and the input signal, a jump command is established regardless of the presence or absence of the input signal, and the intermediate two processes are skipped. Therefore, the target process is executed only once. Furthermore, since the B contact of the D relay acts on the execution of the jump command by a logical product, when the return signal is input, the jump command is not satisfied, and two intermediate processes are executed.
However, since the B contact of D acts on the execution of the target process by a logical product, it is not executed. Similarly, the B contact of D also acts on the B relay by the logical product, and the relay output of B is not established, and the holding operation is released.

[0004]

In recent years, in a machine tool equipped with a programmable controller and a numerical controller, a function capable of promptly finding the cause of an abnormality in order to shorten the time required for repair in the event of a machine failure. The demand for is increasing. For this reason, it is advisable to display the fault by the fuse contact function for each cause of the fault. There was a disadvantage.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a sequence control device having a fuse contact function which can be restored with a simple configuration.

[0006]

In order to achieve this object, a sequence control device of the present invention executes a short-circuit operation only once at a timing when a specific condition occurs, and thereafter, the same condition occurs. Even if it has a contact similar in function to a fuse that operates in a disconnected state, and has a function of restorable fuse contact that restores the function of the initial fuse contact when a return signal is input to the disconnected fuse contact, This is a sequence control device characterized by having the configuration shown in FIG.

More specifically, a fuse contact operation control unit 1 that determines a fuse contact operation based on an input signal and fuse contact information and selects an output signal, a fuse contact information storage unit 2 that manages fuse contact information, and a return signal And a fuse contact return control unit 3 for initializing the fuse contact information.

FIGS. 3A and 3B are a basic function diagram (a) of the fuse contact of the present invention and an operation explanatory diagram (b) of the fuse contact. An input signal for requesting execution of an operation and a return signal for restoring the fuse contact are input to the fuse contact, and the internal state of the fuse contact is used for a contact connected after the fuse contact, an output command, a processing command, and the like. The execution request is output as an output signal.

[0009]

With the above configuration, the provision of the fuse contact information storage section 2 makes it possible to determine whether or not the fuse contact has once performed a short circuit operation, and determine whether the operation of the fuse contact is a short circuit operation or a disconnection operation. The information stored in the fuse contact information storage unit 2 is the fuse contact information, which is information on whether the fuse contact itself has once performed a short-circuit operation. The default value of the fuse contact information is “short circuit”.

The fuse contact operation control unit 1 determines and outputs an output signal from the input signal and the fuse information in the fuse contact information storage unit 2. Only when the input signal is “execute” and the fuse contact information is “short”, the fuse contact is short-circuited. Further, in the above operation, when the fuse contact performs a short-circuit operation, the fuse contact information is stored in the fuse contact information storage unit 2 as “disconnection”. When a return signal is input, the fuse contact return control unit 3 initializes the fuse contact information stored in the fuse contact information storage unit 2 to an initial state “short circuit”.

FIG. 4 is a flowchart showing the basic operation of the fuse contact operation. In this way, the recoverable fuse contact holds the progress of the execution operation of the target process, so that the sequence is not complicated, and the target process is executed only once at the timing when a specific condition occurs. To realize a sequence control device.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows an embodiment in which the recoverable fuse contact is realized by an electric logic circuit. The fuse contact information storage unit 2 includes a flip-flop 5. The flip-flop 5 is initialized at power-on by a reset signal. It is set to "1" by the rising edge of the output signal. Once set to "1", it is not initialized unless a return signal is input.

The fuse contact operation control unit 1 includes a logical product unit 4 of an inverted output of the flip-flop 5 and an input signal, and a delay circuit 7 for delaying the output of the flip-flop 5.
It is composed of The initial state is flip-flop 5
Is an inversion output of "1", and is in a state of waiting for the input signal to change to "1". When the input signal becomes "1", the output signal changes to "1". The rising of this output signal is transmitted to flip-flop 5, and flip-flop 5 is set to "1". Since the input on the flip-flop 5 side of the AND unit 4 becomes "0" after the delay time of the delay circuit, the input signal is masked. Therefore, the output signal becomes "0" regardless of the state of the input signal. Here, the delay circuit 7 is provided to secure a time width of “1” of the output signal.

The fuse contact return control section 3 comprises a logical sum section 6 of a reset signal and a return signal when the power is turned on. The output of the OR unit 6 is connected to the clear terminal of the flip-flop 5, and when a return signal is input, the mask of the input signal is released to initialize the flip-flop 5 and the state returns to the initial state.

As is apparent from the above description, the sequence control device having the resettable fuse contact function according to the present embodiment executes the operation only once at the timing when a specific condition occurs, and thereafter the same condition is satisfied. It has a contact similar to a fuse that does not operate even if it occurs,
Furthermore, an excellent effect is obtained in that the function of restoring the initial function by the return signal can be realized with a very simple circuit configuration without using a complicated self-holding sequence.

[0016]

As described above, the present invention provides a fuse contact operation control unit for determining a fuse contact operation based on an input signal and fuse contact information and selecting an output signal, and a fuse contact for managing the fuse contact information. By providing a fuse contact composed of an information storage unit and a fuse contact return control unit for initializing the fuse contact information by a return signal, a target process can be executed only once at a timing when a specific condition occurs. This makes it possible to realize an excellent sequence control device because the sequence described above can be configured very easily.

[Brief description of the drawings]

FIG. 1 is an internal configuration diagram of a fuse contact that can be restored in the present invention.

FIG. 2 (a) is an electrical logic circuit diagram realizing a recoverable fuse contact of the present invention, and (b) a signal waveform diagram of each part in the logic circuit.

FIG. 3 (a) Basic functional diagram of a fuse contact of the present invention (b) Operation explanatory diagram of the fuse contact

FIG. 4 is a basic operation flowchart of a fuse contact operation according to the present invention.

FIG. 5 is an implementation sequence diagram using self-holding in the related art.

FIG. 6 is an implementation sequence diagram using a jump instruction in a conventional technique.

[Explanation of symbols]

 1 Fuse contact operation control unit 2 Fuse contact information storage unit 3 Fuse contact return control unit

Claims (1)

(57) [Claims] A fuse contact operation control unit that determines a fuse contact operation based on an input signal and fuse contact information and selects an output signal; a fuse contact information storage unit that manages the fuse contact information; A fuse contact comprising a fuse contact return control unit for initializing the fuse contact information, and a fuse disconnected by a return signal and a fuse operation capable of executing a short-circuit operation only once at a timing when a specific condition occurs. A sequence control device having a restorable fuse contact function having a restoring operation for restoring the fuse.