Mitsubishi Electric MELSEC iQ-RJ71EN71 User Manual page 220

When the LINK LED turns off
When the LINK LED turns off, check the following.
Check item
Do the used Ethernet cables conform to the Ethernet standard?
Does the station-to-station distance meet the specifications?
Does the cabling condition (bending radius) meet the specifications?
Is any Ethernet cable disconnected?
Is the switching hub used operating normally?
Are other stations connected to the master/local module operating normally?
If the above actions do not solve the problem, perform the following tests to check for an error.
• Module communication test ( Page 221 Module communication test)
• Cable test ( Page 239 Cable Test)
4 TROUBLESHOOTING
218
4.1 Checking with LED
Action
Replace the cables with the Ethernet cable which conforms the standard. (
MELSEC iQ-R Ethernet/CC-Link IE User's Manual (Startup))
Set the station-to-station distance within range. ( MELSEC iQ-R Ethernet/
CC-Link IE User's Manual (Startup))
Refer to the manual for the Ethernet cable, and correct the bending radius.
Replace the Ethernet cable.
• Check if the switching hub which conforms the standard is used. (
MELSEC iQ-R Ethernet/CC-Link IE User's Manual (Startup))
• Power off and on the switching hub.
• Check if the modules on the other stations are performing data link using
CC-Link IE Field Network diagnostics. ( Page 223 Checking the
Network Status)
• Check the operation status of modules on other stations. ( User's
manual for the module used)