Remote I/O Update Timing Method; Scan Asynchronous Mode - Panasonic MEWNET-F Technical Manual

7.4 Remote I/O Update Timing Method

if the normal I/O update (refresh) and remote I/O update (refresh) are performed after completing the
scan of normal I/Os (on the master station) and remote I/Os, it will take a considerable amount of scan
time for processing remote I/O as a large number of slave stations or I/O points are controlled.
Accordingly, a "Wait time" will be created on the I/O scan time.
In this case, when you select "Scan time asynchronous mode", the I/O will be updated (refreshed)
without waiting for the completion of the scan for remote I/Os. Thus the wait time will be eliminated and
the normal I/O scan time can be shorter.
- The factory default setting is set to "Scan time synchronous mode".
- It is set with the system register No. 36.
- "Scan time asynchronous mode" is effective when the normal I/O processing tiem (scan time) is shorter
than the remote I/O processing time (scan time).When the remote I/O processing time is shorter than the
normal I/O processing time, the I/O update (refresh) is synchronized with the normal I/O processing. So,
even if the "Scan time asynchronous mode" is set, the timing is the same as the scan time synchronous
mode.

7.4.1 Scan Asynchronous Mode

Setting
- System register No. 36: 1
[Operation]
- The normal I/O update (refresh) is performed after completing the processing of normal I/Os even if
remote I/O processing has not been completed yet.
- The remote I/O update (refresh) is performed after completing the processing of remote I/Os.
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