How To Check Errors Using Led Displays; Checking Error Display - Mitsubishi MELSEC-F User Manual

11 TROUBLESHOOTING

11.1 How to Check Errors Using LED Displays

This section describes the errors that can be checked with the LED displays on the
front of the Ethernet module.

11.1.1 Checking error display

The following can be checked with the LED displays on the front of the Ethernet
module.
<Ethernet module LED>
LED name Status to check
Turns off after powering on
1 RUN
the Ethernet module.
2 INIT. Off
3 100M Does not turn on
Turns on after powering on
4 ERR.
the Ethernet module.)
Turns on after powering on
5 COM.ERR the Ethernet module.
Or turns on temporarily
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1) Watchdog timer error
• A watchdog timer (approximately 600 ms) error is detected by the self diagnosis function of the
Ethernet module.
2) Base module power is OFF, or the extension cable is not connected.
1) Failed to re-initialization due to a parameter error
• Check/correct the parameter setting values for the Ethernet modules using a sequence program
or the FX Configurator-EN (GX Developer) and re-download.
2) Base module power is OFF, or the extension cable is not connected.
1) Using 10Mbps HUB
• Initial processing.
• Replace with 100Mbps HUB.
2) Does not turn on using 100Mbps HUB
• Check the connection of the connectors on the Ethernet side and the HUB side.
• Replace the cable.
1) Module parameter setting error
• Check/correct the parameter setting values for the Ethernet modules using the sequence program
or the FX Configurator-EN (GX Developer) and re-download.
2) PLC error
• When the PLC [RUN] LED is off/flashing, or the [ERR.] LED is on, check the content of the error
occurring in the PLC and correct the problem.
3) Ethernet module error (H/W error)
4) Base module power is OFF, or the extension cable is not connected.
1) Check the contents of the error using the error codes stored by the error detection of the following
processing and remove the causes.
• Initial processing
• Fixed buffer send processing
• E-mail send/receive processing
• Open processing
• MC protocol communication processing
• Other processing (processing for which error codes are stored in the error log area)
2) For a list of error codes, see Section 11.4.
Cause/corrective action
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