Mitsubishi Electric MELSEC Q Series User Manual page 216

(5) Assurance of cyclic data integrity (block data assurance per station)
The function of block data assurance per station prevents mixing of previous link scan data and new link scan
data in 1 station data set.
Link scan is performed asynchronously with link refresh in the C Controller module.
Therefore, if 32-bit or higher cyclic data is handled, new data and old data may be mixed.
C Controller
module processing
Link scan
*1 : For data refresh time, refer to the following.
Page 171, Section 11.7.1
When the function of block data assurance per station is set, the C Controller module adjusts link refresh timing
with network module(s), so cyclic data are assured per station.
Data assurance
Data assurance
Data assurance
Data assurance
The function of the block data assurance per station is set in the parameters. Setting location varies depending on
networks.
Network name
CC-Link IE Controller Network
MELSECNET/H
CC-Link IE Field Network
CC-Link
For details of block data assurance per station function, and the other data assurance functions, refer to the
manuals for respective network modules.
To enable block data assurance per station, the following settings are required.
• Set the refresh parameters in Network Parameter.
• Set a value other than 0 for refresh cycle. Enabling the block data assurance per station with refresh cycle set to
0, normal cyclic transmission may be prevented, resulting in a data link error.
214
Refresh cycle Refresh cycle
Link Link
refresh refresh
C Controller module
internal user device
Station No.1 Station No.1 Station No.1
Station No.2 Station No.2 Station No.2
Station No.3 Station No.3 Station No.3
Station No.4 Station No.4 Station No.4
Select "Block data assurance per station is available" in "Block data assurance per
station" from the network parameter "Network Range Assignment" -
"Supplementary Setting".
Select "Block send data assurance per station"/"Block receive data assurance per
station" from the network parameter "Network Range Assignment" -
"Supplementary Setting".
Select "Assure Block Data" in "Block Data Assurance per Station" from master
station's network parameter "Network Range Assignment" - "Supplementary
Setting".
Select "Enable Setting" in "Block Data Assurance per Station" from the network
parameter "Operational Setting".
Refresh cycle
Link
refresh
Network module
link device
Station No.1 Station No.1 Station No.1
Station No.2 Station No.2 Station No.2
Link refresh
Station No.3 Station No.3 Station No.3
Station No.4 Station No.4 Station No.4
Name of setup field
Link
refresh
Data refresh time
Link refresh time
Data assurance
Data assurance
Data assurance
Data assurance