Mitsubishi MELSEC-Q Series User Manual page 86

4
FUNCTIONS
4
- 13
4.3 CC-Link Module Access Function
4.3.1 Block guarantee of cyclic data per station
• If a value is written to the same address area before execution of the
QBF_RefreshLinkDevice function, the area is overwritten with the value
written later.
By writing the value 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.
• If data writing is attempted before completion of the refresh after execution
of the QBF_RefreshLinkDevice function, the data will not be written until
completion of the previous refresh.
C Controller module
User program
QBF_ToBuf function (Manual) 1)
QBF_RefreshLinkDevice function
QBF_ToBuf function (Manual) 2)
QBF_RefreshLinkDevice function
:User program is in standby state.
CC-Link module
Buffer memory
Refresh request
(Data 1) + 2))*1
Figure 4.9 Write operation
CC-Link module
Buffer memory
Refresh request
Refresh request
Figure 4.10 Write operation
Link scan
Link scan
Refresh
Link scan
Link scan
Refresh
(Data 1))
Link scan
Refresh
(Data 2))