Mitsubishi Electric MELSEC-Q00U(J)CPU User Manual page 366

Make the value of the timer limit setting smaller by changing from low speed timer to high speed timer.
Ex.
(Assume that the scan time is 20ms.)
Before change (low-speed timer)
Timer setting value
(100ms 1=100ms)
The following show the examples of the coil and the contact being simultaneously turned on if the values are
set to become "Timer setting value < Scan time + Timer Limit Setting":
When the timer setting value is 1 (1 × 100ms), the scan time is 20ms, and the timer limit setting is 100ms
Ex.
If the coil of the timer (T0) is turned on at the next scan after the values satisfy "Count at execution of the
END instruction  Timer setting value", the coil and the contact are simultaneously turned on because the
values satisfy "Timer current value = Timer setting value" at the start of the timer.
Timer setting value
END
Program
100ms
counting
Count at
execution
0
of the END
instruction
Current
value of T0
OFF
X0
OFF
Coil of T0
OFF
Contact
of T0
364
Scan time Timer Limit Setting
(20ms) (100ms)
Scan time
(1 100ms) (20ms)
END
1
0
0 0
20ms
Timer setting value
(10.00ms 10=100ms)
Timer Limit Setting
(100ms)
END
1
0
ON
20ms 20ms
After change (high-speed timer)
K1
Scan time Timer Limit Setting
(20ms)
Timer setting value
K1
X0
T0
END
0
If the coil is turned on for
this period, the contact
1
is simultaneously turned
on because the count at
execution of the END
instruction becomes
ON
equal to or larger than
the timer setting value.
ON
(10ms)