Mitsubishi MELSEC-A series, Programming Manual

Page: 325 / 508

7. APPLICATION INSTRUCTIONS
7
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123
MELSEC-A
(5) Values of scan time stored in special registers D9017 to D9019 and D9021 are
not cleared though the WDT or WDTP instruction is executed. Values of special
registers may therefore become larger than the WDT values set with parameters
(the A3H, A3M and AnA, A2AS and AnU use fixed WDT values).
Execution Conditions
Program Example WDT
Program used when the setting of watch dog timer is 200 ms and the period of time
from 0 to END (FEDN) instruction is 300 ms depending on the execution conditions
of program.
OFF
ON
Executed
per scan
Executed
per scan
Executed
only once Executed
only once
WDT
WDTP
WDT reset command
Program of
300 ms
Program of
150 ms
Program of
150 ms
WDT
END
END