Mitsubishi Electric Melsec QJ71LP21 Reference Manual page 388

8 TROUBLESHOOTING
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POINT
(1) The target of the network diagnostics is the host's network specified as the
connection destination.
(2) When another station is specified in the transfer setup, only the host
information and other stations' information are available in the network
diagnostics.
(3) The network diagnostics cannot be displayed correctly while the network
module is executing the offline test.
(4) When the link dedicated instruction is used to access the other station
programmable controller during network diagnosis, the execution of the link
dedicated instruction may be delayed.
After taking the following measures, perform network diagnosis processing
and execute the link dedicated instruction.
• Execute the COM instruction.
• Secure the communication processing security time for 2 to 3ms.
For the High Performance model QCPU, Process CPU, and Redundant
CPU, set it by the special register SD315.
For the Universal model QCPU, set it by the service processing setting of
the PLC parameter (PLC system) of GX Developer.
REMARKS
SB and SW
special relay (SB) or the link special register (SW) used for monitoring.
found in the explanations of each item indicate the link
MELSEC-Q
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