Mitsubishi 00JCPU User Manual page 398

9.2.8 Link special relay (SB)
(1) Definition
The Link special relay (SB) is a relay that indicates various communication status and detected errors of
intelligent function modules such as CC-Link IE Controller Network or MELSECNET/H network modules.
Each of this device area is turned on or off according to a factor occurred during data link.
The communication status and errors on the network can be confirmed by monitoring the link special relay (SB).
(2) Number of link special relay points
The points for the link special relay depends on the CPU module.
Basic model QCPU
High Performance model QCPU,
Process CPU, and
Redundant CPU
Remark
For details of the link special relay, refer to the manual for an intelligent function module that has the link special relay.
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Table9.4 Link special relay points for each CPU module type
CPU module Link special relay points
The points for the link special relay in the CPU module is 1024 (SB0 to SB3FF).
To an intelligent function module that has a link special relay, such as a CC-Link
IE Controller Network module or MELSECNET/H network module, 512 points
are assigned.
The points for the link special relay in the CPU module is 2048 (SB0 to SB7FF).
To an intelligent function module that has a link special relay, such as a CC-Link
IE Controller Network module or MELSECNET/H network module, 512 points
are assigned.
The link special relay can be allocated as shown below.
Link special relay
SB0
For 1st network module
SB1FF
SB200
For 2nd network module
SB3FF
SB400
For 3rd network module
SB5FF
SB600
For 4th network module
SB7FF
512
points
512
points
2048
points
512
points
512
points