Справочник Пользователя для Mitsubishi Electronics QCPU

7-386

WDT(P)

Other instructions

Resetting watchdog timer (WDT(P))

WDT(P)

Function

(1) Resets watchdog timer during the execution of a sequence program.

(2) Used in cases where the scan time exceeds the value set for the watchdog timer due to 

prevailing conditions.
If the scan time exceeds the watchdog timer setting value on every scan, change the 
watchdog timer settings at the peripheral device parameter settings.

(3) Make sure that the setting for t1 from step 0 to the WDT instruction and the setting for t2 

from the WDT instruction to the END (FEND) instruction do not exceed the setting value of 
the watchdog timer.

(4) The WDT instruction can be used two or more times during a single scan, but care should be 

taken in such cases, because of the time required until the output goes OFF during the 
generation of an error.

(5) Scan time values stored at the special register will not be cleared even if the WDT or WDTP 

instruction is executed.
Accordingly, there are times when the value for the scan time for the special register is 
greater than the value of the watchdog timer set at the parameters.

Setting 

Data

Internal Devices 

R, ZR

J

\

U

\G

Zn

Constants

Other

Bit

Word

Bit

Word

––

––

Command

WDT

WDTP

Command

WDT

WDTP

Step 0

END (FEND)

WDT

T1

T2