Response Delay In Refresh System - Mitsubishi Electric 700 Series Programming Manual

I/O Processing Method
3.6.2

Response delay in refresh system

This section describes a delay of an output change in response to an input change.
An output change in response to an input change has a delay of up to two scans as
shown in Fig. 2.6.
Ladder example
When Y1E turns on earliest
The Y1E output turns on earliest when the control input terminal turns from OFF to
ON immediately before a refresh. X5 turns on at an input refresh, Y1E turns on at
step 0, and the control output terminal turns on at an output refresh after execution of
the END instruction.
In this case, therefore, a delay of a control output terminal change in response to a
control input terminal change is one scan.
When Y1E turns on latest
The Y1E output turns on latest when the control input terminal turns from OFF to ON
immediately after a refresh. X5 turns on at the next input refresh, Y1E turns on at
step 0, and the control output terminal turns on at an output refresh after execution of
the END instruction.
In this case, therefore, a delay of a control output terminal change in response to a
control input terminal change is two scans.
Fig 3.7 Output Y Change in Response to Input X Change
70
Input refresh Input refresh
0
END
OFF
Control input
terminal
OFF
X5
OFF
Y1E
OFF
Control output
terminal
Input refresh Input refresh
0
ON
OFF
Control input
terminal
OFF
X5
OFF
Y1E
OFF
Control output
terminal
(Maximum 2 scans)
In this ladder, output Y1E turns on when input
X5 turns on.
Output refresh
0 56
END
ON
ON
ON
ON
Delay
(Minimum 1 scan)
Output refresh
0 56
END
END
ON
ON
ON
Delay
0
0