Mitsubishi Electric MELSEC iQ-R-R04CPU - Page 343

21 DEVICES
21.3 User Device
341
21
Accuracy of timers
This sections describes the accuracy of timers.
■Timer (T/ST)
The scan time value measured by the END instruction is added to the current value when the OUT T instruction is executed.
If the timer coil is turned off when the OUT T instruction is executed, the current value is not updated. The maximum
response accuracy of the timer (the time duration from capture of an input (X) to output of it) is "2 scan time + timer time limit
setting".
Ex.
Timer limit setting = 10ms, setting value of T0 = 8 (10ms  8 = 80ms), scan time = 25ms
(1) Accuracy from when the coil of the timer turns on until when the contact of the timer turns on
- (1 scan time + timer limit setting) to (1 scan time)
(2) Timing on when the coil of the timer turns on
(3) Input fetching timing
X0
T0
K8
211 121 1221
2
ON
OFF
OFF
OFF
ON
ON
OFF
ON
3
23 3
232323
25ms 25ms 25ms 25ms 25ms 25ms
0+2=2 2+3=5 5+2=7 7+3=
(1)
(2)
(3)
Program
External input of X0
X0 of the CPU
module
Coil of T0
Contact of T0
Scan time
Measurement at
10ms interval
Count by the END
instruction
Current value of T0
END
processing
END
processing
END
processing
END
processing
END
processing
END
processing