CONTROLLER AND EDITOR

• US 20190310850A1
• Filed: 04/01/2019
• Published: 10/10/2019
• Est. Priority Date: 04/09/2018
• Status: Active Grant

• Current Assignee: Fanuc Corporation
• Original Assignee: Fanuc Corporation
• Inventors: Miyashita, Shouhei
• Granted Patent: US 10,664,274 B2
• Time in Patent Office: Days
• CPC Class Codes: G05B 19/056 Programming the PLC
• CPC Class Codes: G05B 2219/36588 Endless loop
• CPC Class Codes: G06F 9/30032 Movement instructions, e.g. MOVE, SHIFT, ROTATE, SHUFFLE
• CPC Class Codes: G06F 9/30065 Loop control instructions; iterative instructions, e.g. LOOP, REPEAT

Abstract

A controller and an editor that enable a ladder program to escape an infinite loop are provided.

A controller that can detect a loop process being stuck in an infinite loop during execution of a ladder program includes an infinite loop escape unit for escaping the infinite loop by forcefully making an execution condition for a jump instruction false when the infinite loop occurs, the jump instruction being included in the loop process.

Claims

1. A controller that can detect a loop process being stuck in an infinite loop during execution of a ladder program, the controller comprising:

an infinite loop escape unit for escaping the infinite loop by forcefully making an execution condition for a jump instruction false when the infinite loop occurs, the jump instruction being included in the loop process.

2. The controller according to claim 1, wherein the infinite loop escape unit escapes the infinite loop by referring to an infinite loop occurrence condition information table recording at least a state of an execution condition signal on normal completion of the loop process, and forcefully overwriting the current execution condition signal with the execution condition signal on the normal completion.

3. The controller according to claim 1, wherein the infinite loop escape unit escapes the infinite loop by forcefully overwriting a signal state of a closed contact provided within the jump instruction.

4. The controller according to claim 2, further comprising:

an infinite loop detection unit for recording the execution condition signal of the loop process that may cause the infinite loop, in the infinite loop occurrence condition information table.

5. The controller according to claim 2, further comprising:

an infinite loop detection unit for recording the state of the execution condition signal on the normal completion of the loop process in the infinite loop occurrence condition information table during execution of the ladder program.

6. An editor for editing a ladder program, the editor comprising:

an infinite loop detection unit for recording an execution condition signal of a loop process that may cause the infinite loop, in an infinite loop occurrence condition information table.