Mitsubishi Electric MELSEC iQ-R Series User Manual page 125

Modules cannot join a network.
If the modules cannot join a network, check the following.
Check item
Is the RUN LED of the own station turned off?
Is the ERR LED of the own station turned on?
Is the set station number greater than the number of connected modules?
Check 'Loop usage status of each station' (SW009C to SW009F).
Is wiring performed correctly?
Is any cable disconnected?
Is the link monitoring time correctly set?
In the optical loop system, do not reset the CPU modules of adjacent stations on the wiring at the same time.
Otherwise, the modules may not join the network. When simultaneous initialization is required for adjacent
stations, turn the power on and off.
When a station is disconnected from the network
The following is the action to be taken when a station in data link is disconnected.
Check item
Is the ambient temperature for the module within the specified range?
If the above action does not solve the problem, perform the self-diagnostics test to check for hardware failure. (Page 95
Self-diagnostics test)
When a station is repeatedly disconnected and reconnected
The following lists the actions to be taken when a station in data link is repeatedly disconnected and reconnected.
Check item
Does the communication cable used conform to the standard?
Does the length of the communication cable meet the specifications?
Does the cabling condition (bending radius) meet the specifications?
Is any cable disconnected?
If the above action does not solve the problem, perform the self-diagnostics test to check for hardware failure. (Page 95
Self-diagnostics test)
Action
Perform troubleshooting for when the RUN LED turns off. ( Page 90
When the RUN LED turns off)
Perform troubleshooting for when the ERR LED turns off. ( Page 90 When
the ERR LED turns on or is flashing)
Correct the station number so that it is within the number of connected
modules.
Correct the cable connection status of the faulty part.
Check the wiring status using the loop test of the MELSECNET diagnostics.
Correct the system configuration. Check the status of each station and check
the faulty area.
Set the link monitoring time to the maximum and check if the modules can join
the network.
Action
Keep the ambient temperature within the specified range by taking action such
as removing heat source.
Action
Replace the communication cable with one conforming to the standard.
 MELSEC iQ-R MELSECNET/H Network Module User's Manual (Startup)
Set the length of the communication cable within range.
 MELSEC iQ-R MELSECNET/H Network Module User's Manual (Startup)
Refer to the manual for the communication cable, and correct the bending
radius.
Replace the cable.
4.4 Troubleshooting by Symptom
4 TROUBLESHOOTING
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