Mitsubishi Electric MELSEC Q Series Reference Manual page 243

(c) When networks are connected in a loop configuration
Be sure to configure the settings correctly so that requests and responses will take the same route.
A response from the request target is passed back to the station that relayed the request.
Therefore, if a different route is set, data cannot be transferred and an error will occur.
Request
source
3
1
No.2
4
2
B
No.3
1
A
5
(d) On a relay station in the multiple CPU system, when different control CPUs are set
for the network modules
Set the same routing parameters to each of the control CPUs.
"A" shows a route from the request source
to the target. "B" and "C" show routes
1
from the target to the source.
Set parameters properly so that "C" will not occur.
No.1 2 4 No.8
3
2
No.7
1
1
No.6
3
2
No.4 3 4 No.5
CHAPTER 6 PARAMETER SETTING
C
Request
target
6
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