MITSUBISHI ELECTRIC 700 Series - Manual (Page 76)

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Scan Time
3
SEQUENCE PRO
G
RAM
M
ING
3.7 Scan Time
(1) Scan time
A scan time is a time from when sequence program operation is executed from
step 0 until step 0 is executed again.
The scan time of each scan is not equal, and changes depending on whether the
used instructions are executed or not.
Fig 3.8 Scan Time
(2) Scan time confirmation
(a)The scan time from the END instruction to the next END instruction is timed in
the PLC, and stored into the special registers D9017 to D9019 in units of
10ms.
1) Data stored into special registers D9017 to D9019
• D9017 ........... Minimum value of scan time
• D9018 ........... Present value of scan time
• D9019 ........... Maximum value of scan time
2) Scan time accuracy
The accuracy of the scan time observed in the PLC is 10ms.
For example, when the D9018 data is 5, the actual scan time is 40ms to
60ms.
Scan time
END END 0 0
Sequence program
END processing
Timer/counter count processing
Self-diagnostic checks