Mitsubishi Electric MELSEC iQ-R Series User Manual page 184

• Condition judgment in a refresh cycle of 100 ms
In the figure below, bit data turns ON twice. At the first time, conditions are not satisfied (the ON state cannot be detected)
because the bit data turns ON outside of the refresh cycle. At the second time, the conditions are satisfied because the bit
data turns ON during the refresh cycle.
ON
(1)
(2)
0 100ms 200ms
(1) Bit data
(2) Judging conditions in the refresh cycle of 100 ms
In addition, condition judgment and condition satisfaction judgment are performed in every refresh cycle. Therefore, maximum
two refresh cycles need to be considered for satisfying certain conditions.
• Condition judgment when setting a refresh cycle to 600 ms and turning an input signal ON for one second
When the input ON state is detected at 600 ms, a condition that an input signal turns ON for one second will be detected at
1800 ms where condition satisfaction judgment is performed. If the input signal turns OFF before 1800 ms, the condition will
not be satisfied.
ON
(1)
(2)
0ms 600ms 1200ms 1800ms 2400ms
(1) Bit data
(2) Judging conditions in the refresh cycle of 600 ms
Checking the interval
The following shows the method for checking the interval (maximum value/minimum value/current value) at which the fixed
cycle processing function runs.
■Checking with special registers
The interval at which the function runs is stored in special registers (SD520 to SD525). (Page 276 Special Register List)
18 FIXED CYCLE PROCESSING FUNCTION
182
ON
300ms 400ms
1s
OFF