7.17 Other Instructions
7.17.1 Resetting watchdog timer
7-347
7
APPLI
C
A
T
IO
N
INSTRUCTIONS
WDT
WDT
7.17
Other Instructions
7.17.1
Resetting watchdog timer
WDT
Function
(1) Resets a 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 on parameter settings of the peripheral.
(3) Make sure that the setting for t1 from step 0 to the WDT(P) instruction and the setting for t2
from the WDT(P) instruction to the END (FEND instruction) not to exceed the setting value
of the watchdog timer.
(4) The WDT(P) instruction can be used two or more times during a single scan, but a care
should be taken in such cases, because longer time is required for turning OFF the output at
the error occurrence.
WDT(P)
P: Executing condition
:
indicates any of the following
instructions.
WDT
WDTP
Input argument,
EN:
Executing condition
:Bit
Output argument,
ENO:
Execution result
:Bit
Setting
data
Internal device
R, ZR
J
\
U
\G
Zn
Constant
Others
Bit
Word
Bit
Word
−
−
Universal
UD
High
Performance
Structured ladder
ST
W
D
T
EN
ENO
W
D
T
(EN);
ENO:=
S
tep
0
EN
D
(FEN
D
)
W
D
T
t
1
t
2
Summary of Contents for MELSEC Q Series
Page 1: ...Structured Programming Manual Mitsubishi Programmable Controller QCPU Common Instructions ...
Page 2: ......
Page 14: ...A 12 MEMO ...
Page 340: ...6 178 MEMO MTR ...
Page 708: ...7 368 MEMO ...
Page 776: ...8 68 MEMO ...
Page 796: ...9 20 MEMO ...
Page 804: ...App 8 MEMO ...
Page 812: ...Index 8 MEMO ...
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