Mitsubishi Electric Q12DCCPU-V - Page 161

5
ACCESS VIA NETWORK MODULES
5.2 CC-Link Module Access Function
5.2.1 Block data assurance per station
5 - 7
1
OVERVIEW
2
SYSTEM CONFIGURATION
3
SPECIFICATIONS
4
FUNCTIONS
5
ACCESS VIA NETWORK MODULES
6
PREPARATORY PROCEDURES AND SETTING
7
I/O NUMBER ASSIGNMENT
8
MEMORIES AND FILES
(a) Automatic cyclic data refresh
1) Execute the QBF_ToBuf function with "automatic" specified for "CC-Link
refresh method" of the third argument (ulOffset).
2) In the timing of the next link scan, data are refreshed.
• If execution of the QBF_ToBuf function is attempted before completion of the
previous refresh, data writing is suspended until completion of the refresh.
POINT
Up to a time of up to one link scan may be required for refreshing the written data
after execution of the QBF_ToBuf function.
Figure 5.5 Write operation
Figure 5.6 Write operation
Buffer memory
Link scan
C Controller module CC-Link module
Refresh
Link scan
Refresh request
1)
2
)
QBF_ToBuf function
(Automatic), Writing data
User program
Buffer memory
Link scan
C Controller module CC-Link module
Link scan
: User program is in standby state.
QBF_ToBuf function
(Automatic), Writing data 1)
Link scan
Refresh request 1)
Refresh
(Data 1))
Refresh request 2)
Refresh
(Data 2))
QBF_ToBuf function
(Automatic), Writing data 2)
User program