Title:
PROGRAMMABLE CONTROLLER
Document Type and Number:
Japanese Patent JPS60235205
Kind Code:
A
Abstract:
PURPOSE:To adjust the timer time of a watchdog timer systematically by writing preliminarily a prescribed timer time extending instruction in accordance with the case where an element which increases the execution time of one cycle is added on a user program. CONSTITUTION:The watchdog timer of a programmable controller counts a preliminarily set certain time in response to a start signal given from a processor 1 to a watchdog counter 8. The processor 1 is reset when time counting is completed, and a time interrupting timer counts a certain time shorter than said time of the watchdog timer repeatedly by a time interrupting counter 9 and interrupts the processor each time when time counting is completed. If the prescribed timer time extending instruction is written preliminarily in a memory 4 in case that the element which increases the execution time of one cycle is added on the user program, the number of extensions is set to a reset number counter and the counter 8 is reset when the extending instruction is discriminated at the instruction execution time, and the reset number is counted down for every interruption from the counter 9 to perform the extension processing.
Inventors:
TOMITA KAZUAKI
YAMAMOTO KEIJI
NAKAMURA MITSURU
YAMAMOTO KEIJI
NAKAMURA MITSURU
Application Number:
JP9160284A
Publication Date:
November 21, 1985
Filing Date:
May 08, 1984
Export Citation:
Assignee:
OMRON TATEISI ELECTRONICS CO
International Classes:
G06F11/30; G05B19/02; G05B19/05; G05B23/02; (IPC1-7): G05B19/02; G05B23/02; G06F11/30
Attorney, Agent or Firm:
Shigenori Wada