Access By Link Refresh Function - Mitsubishi Electric MELSEC Q Series User Manual

13.2.1

Access by link refresh function

Access by link refresh function is a method to access internal user device(s) of the C Controller module from the user
program. Internal user devices of the C Controller module performs link refresh with the network module link device to
communicate data.
User program
(1) Internal user device
The C Controller module uses the following internal user devices to share data with network module(s).
• Link relay (B)
• Link register (W): 16-bit number information
(2) Link refresh and refresh cycle
Link refresh is a processing to communicate device data between the internal user devices of the C Controller
module and the network module link device. Link refresh is performed in each refresh cycle of the C Controller
module (Page 175, Section 11.7.3).
(3) Parameters to set
To perform link refresh, set the following parameters.
(a) Refresh parameter settings
To perform link refresh, it is necessary to set the refresh parameters.
The refresh parameters are parameters to transfer the network module link device(s) to the internal user
device(s) on the C Controller module to make them available for the user program.
For a setting example of the refresh parameter, refer to the following.
Page 227, Section 13.4.1 (2)(a), Page 234, Section 13.4.3 (2)(a)
(b) Device point setting for internal user devices
Device points can be changed with CCPU parameters in Setting/monitoring tools for the C Controller module.
Initial setting values without change are listed below.
Internal user device
Link register (W)
(c) Setting of block data assurance per station
The function of the block data assurance per station is set in the network parameters. Setting location varies
depending on networks. (Page 214, Section 13.2.1 (5))
212
C Controller module
Link refresh
Internal user
device
: ON/OFF information
Number of points
(initial value)
Link relay (B)
Q24DHC-V
network module
Link
device
Range of use (initial value)
8192
8192
Q24DHC-VG Q24DHC-LS Q26DHC-LS
network module
Link
Link
device
scan
B0 to B1FFF
W0 to W1FFF
Q12DC-V