JPH05150809A - Sequence controller with restorable fuse contact function - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a sequence control device in which a sequence that executes a target process only once at a timing when a specific condition occurs is simply configured. [Structure] 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 that enables the above-mentioned operation. A fuse contact including a fuse contact restoration control unit 3 for initializing fuse contact information, and a fuse operation capable of executing a short-circuit operation only once at a timing when a specific condition occurs, and a fuse broken by a restoration signal A sequence control device having a recoverable fuse contact function having a recovery operation for recovering a fuse.

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, a self-holding sequence has been used. Figure 5
Is an example in which the function of the self-holding sequence is applied.
In the configuration in which the target process is executed when the B relay output is established, the C relay output holds that the process was once executed. Since the B contact of the C relay acts as a logical product on the B relay output, the B relay output is established only once. Therefore, the target process is executed only once. Further, since the B contact of the D relay acts as a logical product on the C relay output, when the return signal is input, the C relay output is not established and the holding operation is released.

FIG. 6 shows an example using a jump instruction. Normally, the jump instruction causes the intermediate two processes to be skipped without being executed. If the jump command is not satisfied, the target process is executed and the B relay output is also satisfied.
It retains that the process has been executed once. Since the contact point of B acts as an OR with 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 as a logical product for executing the jump command, when the return signal is input, the jump command fails and the intermediate two processes are executed.
However, since the B contact of D acts as a logical product for the execution of the target processing, it is not executed. Similarly, the B contact of D also acts on the B relay by a logical product, 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 discovering the cause of an abnormality in order to shorten the time required for repair when the machine is out of order. The demand for is increasing. Therefore, it is good to display the failure by the fuse contact function for each cause of failure.However, in the method using the conventional self-holding sequence, etc., the number of relays used is large and the sequence becomes very complicated. There was a drawback that

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a sequence control device having a fuse contact function that can be restored with a simple structure.

[0006]

In order to achieve this object, the sequence control device of the present invention executes a short-circuiting operation only once at a timing when a specific condition occurs, and thereafter, the same condition occurs. Even if there is a contact that works similar to a fuse that operates in the state of disconnection, a recoverable fuse contact function that restores the function of the initial fuse contact when a return signal is input to the above-mentioned disconnected fuse contact The sequence control device is characterized by having the structure shown in FIG.

That is, 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. The fuse contact recovery controller 3 for initializing the fuse contact information is provided.

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

[0009]

By having the fuse contact information storage unit 2 with the above configuration, it is possible to judge whether the fuse contact has once executed the short-circuiting operation and to decide whether the operation of the fuse contact is the short-circuiting operation or the disconnection operation. The information stored in the fuse contact information storage unit 2 is the fuse contact information, which is information about whether or not the fuse contact itself has once short-circuited. The fuse contact information of the initial value 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-circuit”, 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 "open circuit". The fuse contact restoration control unit 3 initializes the fuse contact information stored in the fuse contact information storage unit 2 to the initial state “short circuit” when a restoration signal is input.

FIG. 4 is a basic operation flowchart of the fuse contact operation. In this way, the recoverable fuse contact holds the progress of the execution operation of the target process, so the target process is executed only once when a specific condition occurs without complicating the sequence. To realize a sequence control device.

[0012]

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

The fuse contact operation control unit 1 delays the output of the logical product unit 4 and the flip-flop 5 of the inverted output of the flip-flop 5 and the input signal.
It consists of and. Initial state is flip-flop 5
Since the inverting output of is a "1", the input signal is in a state of waiting for a change to "1". When the input signal becomes "1", the output signal changes to "1". The rising edge of this output signal is transmitted to the flip-flop 5, and the flip-flop 5 is set to "1". The input signal on the flip-flop 5 side of the logical product section 4 becomes "0" after the delay time of the delay circuit, so that the input signal is masked. Therefore, the output signal becomes "0" regardless of the state of the input signal. The delay circuit 7 here is provided in order to secure the time width of "1" of the output signal.

The fuse contact restoration control unit 3 is composed of a logical sum unit 6 of a reset signal and a restoration 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 the return signal is input, the flip-flop 5 is initialized so that the mask of the input signal is released and the initial state is restored.

As is apparent from the above, 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. Has a contact similar to a fuse that does not perform its operation even if it occurs,
Further, an excellent effect is obtained in that the function of recovering the initial function by the return signal can be realized by a very simple circuit configuration without using a complicated self-holding sequence.

[0016]

As described above, according to the present invention, 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, and a fuse contact that manages the fuse contact information. By including a fuse contact composed of an information storage unit and a fuse contact restoration control unit that initializes the fuse contact information by a restoration signal, it is possible to execute the target processing only once when a specific condition occurs. It is possible to realize an excellent sequence control device by extremely easily constructing the sequence.

[Brief description of drawings]

FIG. 1 is an internal configuration diagram of a recoverable fuse contact according to the present invention.

FIG. 2A is an electrical logic circuit diagram that realizes the recoverable fuse contact of the present invention. FIG. 2B is a signal waveform diagram of each part in the logic circuit.

FIG. 3A is a basic functional diagram of the fuse contact of the present invention. FIG. 3B is an operation explanatory diagram of the fuse contact.

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

FIG. 5 is an execution sequence diagram using self-holding in a conventional technique.

FIG. 6 is an execution sequence diagram using a jump instruction in the 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)

[Claims] 1. 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, and a reset signal. A fuse contact including a fuse contact restoration control unit that initializes the fuse contact information, and enables a short-circuit operation only once when a specific condition occurs. A sequence control device having a recoverable fuse contact function having a recovery operation for recovering a fuse.