Led Indicators - AutomationDirect C0-USER-M Manual

Chapter 6: Troubleshooting

LED Indicators

The CLICK PLC performs many pre-defined diagnostic routines with every PLC scan, using
onboard diagnostics that can detect various errors or failures in the PLC. LEDs on the face of
the PLC will indicate for specific errors.
The 3 LEDs located next to the RUN/STOP switch power, (PWR, RUN and ERR) indicate
the status of the PLC unit. The remainder of the LED indicators are discussed in later sections
of this chapter:
•
TX1/RX1/TX2/RX2/TX3/RX3 & LINK/ACT – Chapter 2
LED Status Meaning
The PLC is powered
On
correctly.
The PLC input
Blinking power is not
PWR
sufficient.
There is no power
Off
to the PLC.
The PLC is in RUN
On
mode.
The PLC is
initializing the
Blinking
C0-04RTD or
RUN
C0-04THM.
The PLC is in STOP
Off
mode.
On There is an error.
ERR
Blinking There is a warning.
Off There is no error.
Errors (ERR LED on)
•
• LED indicators for I/O – Chapter 2
Errors which may cause the system to function improperly, perhaps causing a safety problem. The PLC will automatically
switch from RUN Mode to STOP Mode. (In STOP Mode all outputs are turned off.) If the PLC is already in STOP Mode
when an error is detected, the PLC will not allow a transition to RUN Mode until the error has been corrected.
Examples of errors:
• I/O module error
• System configuration error
• Memory check error
• Project file error
Warnings (ERR LED blinking)
Warnings that require attention, but do not cause improper operation. They do not cause or prevent any PLC mode
transitions. The application program can use system control bits to detect warnings, and even take the system to an orderly
shutdown or switch the PLC to STOP Mode if desired. Examples of warnings:
• Lost SRAM data
• Battery low voltage
6–4 CLICK PLC Hardware User Manual, 6th Edition, Rev. F – C0-USER-M
No action is necessary.
Check the voltage on the terminal located on the bottom of the PLC. The input voltage
should be 20-28 VDC. Also check the power input wiring & terminal connections. The
power supply may need to be replaced.
Check the voltage on the terminal located on the bottom of the PLC. The input voltage
should be 20-28 VDC. Also check the power input wiring & terminal connections. The
power supply may need to be replaced.
If the toggle switch next to the LED indicators is in RUN position, no action is necessary. If
the toggle switch is in STOP position, cycle power the PLC. If the PLC unit starts up in Run
mode, it means that the PLC unit does not recognize the toggle switch position correctly,
and the PLC unit must be replaced.
When a C0-04RTD or C0-04THM is installed in the CLICK PLC system, the RUN LED blinks
for up to 11 seconds to indicate that the PLC unit is initializing the analog input module after
power-up. If the RUN LED keeps blinking after the initial 11 seconds, power cycle the CLICK
PLC system. If the symptom remains, replace the PLC unit and/or the analog input module.
If the toggle switch next to the LED indicators is in STOP position, no action is necessary.
If the switch is in RUN position and you want to put the PLC unit in Run mode, toggle
the switch to STOP position and then back to RUN position. If the RUN LED stays off,
connect the CLICK programming software to read the error information. See the "Error
Codes" section at the end of this chapter for error message instructions.
Connect the CLICK programming software to check the error. See the "Error Codes"
section at the end of this chapter for error message instructions.
Warnings do not prevent the PLC unit from running. However, you should check what
warnings are active. Connect the CLICK programming software to read the warning
information. See the "Error Codes" section at the end of this chapter for error message
instructions.
No action is necessary.
Necessary action