Chapter 10 Troubleshooting; Before Troubleshooting; Check By Visual Inspection - Mitsubishi Electric MELSEC-Q Series User Manual

CHAPTER 10
This chapter describes how to identify and eliminate the error cause in the master module.
10.1

Before Troubleshooting

Check that the POWER LED of the power supply module and the MODE LED of the CPU module are on. If they are
off, perform the troubleshooting of the CPU module.
 User's Manual (Hardware Design, Maintenance and Inspection) for the CPU module used
10.2

Check by Visual Inspection

Check that the communication cables and wires are not disconnected and check the following items.
(1) Checking the LED status of the master module
With the following LEDs, errors regarding the operating status and communications of the master module can be
checked. When the LEDs are in the following status, settings and wiring need to be corrected.
1.
Check the RUN LED of the master module.
If the RUN LED does not turn on, perform the following troubleshooting.
 Page 98, Section 10.6
2.
Check the LINK LED of the master module.
If the LINK LED does not flash, perform the following troubleshooting.
Page 98, Section 10.6
3.
Check the ALM LED of the master module.
If the ALM LED is flashing or on, perform the following troubleshooting.
Page 98, Section 10.6
(2) Checking the operating status of the slave module
Check that there is no error in the slave module. For the troubleshooting of the slave module, refer to Page 100,
Section 10.7.
• Slave module data (I/O data and parameter data) cannot be checked.
• Slave module data (I/O data and parameter data) are unstable.
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TROUBLESHOOTING