Mitsubishi Electric Q12DCCPU-V User Manual page 162

5
ACCESS VIA NETWORK MODULES
5
- 8 5.2 CC-Link Module Access Function
5.2.1 Block data assurance per station
(b) Manual cyclic data refresh
1) Execute the QBF_ToBuf function with "manual" specified for "CC-Link refresh
method" of the third argument (ulOffset).
2) Use the QBF_RefreshLinkDevice function to issue a refresh request.
3) In the timing of the next link scan, refresh is performed.
C Controller module
User program
1)
QBF_ToBuf function (Manual)
2)
QBF_RefreshLinkDevice function
3)
• If data are written to the same address area before execution of the
QBF_RefreshLinkDevice function, the area will be overwritten with the data
refreshed later.
By writing the data to another address area, both of the data can be written.
C Controller module
User program
QBF_ToBuf function (Manual) 1)
QBF_ToBuf function (Manual) 2)
QBF_RefreshLinkDevice function
*1 Since writing these data to the same address overwrites the area in the buffer memory,
newly written data are refreshed.
If written to different addresses, both data are refreshed.
CC-Link module
Buffer memory
Refresh request
Figure 5.7 Write operation
CC-Link module
Buffer memory
Refresh request
(Data 1) + 2))*1
Figure 5.8 Write operation
Link scan
Link scan
Link scan
Refresh
Link scan
Link scan
Refresh