Chapter 4 Troubleshooting; Checking With Leds - Mitsubishi Electric MELSEC iQ-R Series User Manual

4
TROUBLESHOOTING
This chapter describes troubleshooting of the RJ71DN91.
4.1

Checking with LEDs

This section describes troubleshooting using the LEDs. If an error has occurred in the RJ71DN91, identify the error cause
using the engineering tool. ( Page 50 Checking the Module Status)
Error status can be determined by status of the RUN LED and the ERR LED.
RUN LED ERR LED
Off 
On Flashing
On On
*1 When multiple errors occur, the error status is displayed in the order of major, moderate, and minor.
When the RUN LED turns off
When the RUN LED turns off after powering on the RJ71DN91, check the following.
Check item
Is the RJ71DN91 mounted correctly?
Is the CPU module reset or turned off while accessing the file?
If the above action does not solve the problem, perform the hardware test to check for hardware failure. ( Page 52
Hardware test)
When the ERR LED turns on or is flashing
When the ERR LED turns on or is flashing, check the following.
Check item
Does any error occur in the module diagnostics?
If the above action does not solve the problem, perform the hardware test to check for hardware failure. ( Page 52
Hardware test)
When the MS LED turns off
When the MS LED turns off, check the following.
Check item
Is the power of the module on?
When the NS LED turns off
When the NS LED turns off, check the following.
Check item
Is the power supply for network being initialized?
4 TROUBLESHOOTING
48
4.1 Checking with LEDs
*1
Error status Description
Major error • The power of the module is off.
• An error such as hardware failure or memory failure. The module stops operating.
Moderate error An error, such as parameter error, which affect module operation. The module stops
operating.
Minor error An error such as communication failure. The module continues operating.
Action
If not, mount RJ71DN91 on the base unit correctly.
Reset or turn off and on the CPU module to restart RJ71DN91.
Then, write the parameter again.
Action
Take the actions displayed on the window.
Action
Turn on the module.
Action
If the NS LED remains off even after a few seconds, check if the power supply
for network is on.