Mitsubishi MELSEC-Q Series User Manual page 85

4
FUNCTIONS
POINT
(b) Manually refreshing cyclic data
• If execution of the QBF_ToBuf function is attempted before completion of
the previous refresh, data writing will not start until completion of the
refresh.
C Controller module
User program
QBF_ToBuf function (Auto)
Writing data 1)
QBF_ToBuf function (Auto)
Writing data 2)
:User program is in standby state.
A time of up to one link scan may be required from execution of the QBF_ToBuf
function until refresh of written data.
1) Execute the QBF_ToBuf function with "manual" specified for "The link
refreshing method of the CC-Link link" of the third argument (ulOffset).
2) Issue a refresh request with the QBF_RefreshLinkDevice function.
3) At the timing of the next link scan, data are refreshed.
C Controller module
User program
1)
QBF_ToBuf function (Manual)
2)
QBF_RefreshLinkDevice function
3)
4.3.1 Block guarantee of cyclic data per station
CC-Link module
Buffer memory
Refresh request 1)
Refresh request 2)
Figure 4.7 Write operation
CC-Link module
Buffer memory
Refresh request
Figure 4.8 Write operation
4.3 CC-Link Module Access Function
Link scan
Link scan
Refresh
(Data 1))
Link scan
Refresh
(Data 2))
Link scan
Link scan
Link scan
Refresh
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