Chapter 3 Troubleshooting; Checks Using Leds; When The Run Led Flashes Or Turns Off; When The Err Led Turns On - Mitsubishi Electric MELSEC iQ-R Series User Manual

3
TROUBLESHOOTING
This chapter describes errors that may occur when the temperature control module is used and troubleshooting.
3.1

Checks Using LEDs

Checking the display status of LEDs is the primary diagnostics without an engineering tool, narrowing down the causes of the
error that has occurred.
A state of the temperature control module can be checked with the RUN LED, ERR LED, ALM LED, and HBA LED. The
following table shows the correspondence between each LED status and each state of the temperature control module.
Name Description
RUN LED Indicates the operating status of the temperature control module.
ON: The module is operating normally.
Flashing:The module is selected as a module for the online module change.
OFF: 5V power supply has been shut off, a watchdog timer error has occurred, or replacing the module is allowed in the process of the
online module change.
ERR LED Indicates the error status of the temperature control module.
ON: An error has occurred.
OFF: Normal operation
ALM LED Indicates the alert status of the temperature control module.
ON: An alert has occurred.
Flashing:A temperature process value (PV) is out of the temperature measuring range, a loop disconnection has been detected, or a
temperature sensor has not been connected.
OFF: No alert has occurred.
HBA LED Indicates the heater disconnection detection status or the output off-time current error status of the R60TCTRT2TT2BW and
R60TCRT4BW.
ON: A heater disconnection or an output off-time current error has been detected.
OFF: No heater disconnection or output off-time current error has occurred.
*1 For details, refer to the following:
Page 146 List of Error Codes

When the RUN LED flashes or turns OFF

When the RUN LED flashes or turns OFF, check the following items:
Check item
Is the power supplied?
Is the capacity of the power supply module enough?
Has a watchdog timer error occurred?
Is replacing the module allowed in the process of the
online module change?

When the ERR LED turns ON

When the ERR LED turns ON, check the following items:
Check item
Has an error occurred?
Is the cold junction temperature compensation
resistor disconnected or loose? (for the
R60TCTRT2TT2 and the R60TCTRT2TT2BW only)
*1
Corrective action
Check that the supply voltage of the power supply module is within the rated range.
Calculate the current consumption of the installed CPU module, I/O module, and intelligent function
module to check whether the power capacity is sufficient.
• Reset the CPU module or turn ON the power supply again.
• Replace the temperature control module.
Perform the online module change. For details, refer to the following:
MELSEC iQ-R Online Module Change Manual
Corrective action
Check 'Latest error code' (Un\G0), and take a corrective action described in List of Error Codes.
Page 146 List of Error Codes
Properly connect the cold junction temperature compensation resistor.
3 TROUBLESHOOTING
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3.1 Checks Using LEDs
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