9 -
3
9.
MAINTENANCE FUNCTION
(3) Processing when the watchdog timer times out
When the scan time exceeds the set value of the watchdog timer, a watchdog timer
error occurs and the PLC operates as follows.
(a) All PLC outputs are turned OFF.
(b) The RUN LED on the front of the CPU module goes off and the ERROR LED
flickers.
(c) SM1 turns ON and the error code is stored in SD0.
REMARK
The watchdog timer can be reset by a WDT instruction in the sequence program.
However, the scan time value is not reset and scan time is measured up to the END
instruction.
POINT
An error occurs within 0ms to 10ms in the measured time for watchdog timer.
Summary of Contents for Q2ACPU
Page 1: ......
Page 2: ......
Page 221: ...12 12 12 OVERVIEW OF PROCESSING PERFORMED BY THE QnACPU ...
Page 222: ...12 13 12 OVERVIEW OF PROCESSING PERFORMED BY THE QnACPU ...
Page 237: ...12 28 12 OVERVIEW OF PROCESSING PERFORMED BY THE QnACPU MEMO ...
Page 271: ...16 13 16 POWER SUPPLY MODULE 4 Names and description of parts of the A66P ...
Page 343: ...21 21 13 MAINTENANCE AND INSPECTION 21 4 2 Replacement of the fuse for an output module ...
Page 357: ...22 12 22 TROUBLESHOOTING ...
Page 359: ...22 14 22 TROUBLESHOOTING MEMO ...
Page 429: ...App 32 APPENDICES Trigonometric function Classification Symbol Description ...
Page 537: ...App 140 APPENDICES REMARK 1 Message 1 An error code is displayed in 2 Alert 1 3 Alert 2 ...
Page 539: ...App 142 APPENDICES 2 Q2ACPU Q2ACPU S1 modules Unit mm inch ...
Page 541: ...App 144 APPENDICES 2 A66P power supply module Unit mm inch ...
Page 543: ...App 146 APPENDICES 3 A35B base unit 4 A38B A38HB A38HBEU base unit Unit mm inch Unit mm inch ...
Page 567: ...MEMO ...
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