Troubleshooting By Symptom; Cyclic Transmission Cannot Be Performed; Transient Transmission Cannot Be Performed - Mitsubishi Electric MELSEC-L SSCNETIII/H User Manual

11.5

Troubleshooting by Symptom

Troubleshooting methods are described by symptom. Perform these troubleshooting actions when cyclic and/or
transient transmissions are not possible with the target station even though no error is detected in the head module.
If an error has occurred in an intelligent function module installed with the head module, identify the cause of the error
by GX Works2. ( Page 83, Section 11.2)
• Before starting the troubleshooting by symptom, check that the POWER LED of the power supply module is on.
For troubleshooting of the power supply module, refer to  MELSEC-L CPU Module User's Manual (Hardware
Design, Maintenance and Inspection).
• When the troubleshooting by symptom cannot solve the problem: Perform the unit test on the head module to
check for a hardware error. ( Page 44, Section 6.4)
11.5.1

Cyclic transmission cannot be performed.

When cyclic data are not delivered to other stations, or when cyclic data from the Motion controller cannot be received,
use the following troubleshooting methods.
Check item
Is the REM. LED of the head module on?
Are the I/O assignment settings of PLC parameter correct?
Is the switch of the head module set to "RUN"?
Is the RUN LED of the head module on?
If the above actions do not solve the problem, check if there is any error in the refresh device setting for the CPU
module configured by the Motion controller. ( Programming Manual (COMMON) for the Motion controller used)
11.5.2

Transient transmission cannot be performed.

If transient transmissions are not executable with the target station, check that the station numbers set with the rotary
switches of the head module are set correctly. ( Page 20, CHAPTER 2)
If the REM.LED is flashing or off, perform the troubleshooting by the LEDs. (
Page 89, Section 11.4)
Set the I/O assignment correctly. ( Page 63, Section 7.1 (6))
Set the switch of the head module to "RUN".
If the RUN LED is flashing or off, perform the troubleshooting by the LEDs. (
Page 89, Section 11.4)
CHAPTER 11 TROUBLESHOOTING
Action
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