G9SE Fault Detection

Updated May 20, 2022

Scenario

The power indicator light on your G9SE unit is blinking, or other indicator lights are blinking when the power indicator light is on.

Additionally, the G9SE is not outputting an 'ON' signal.

Issue

A fault has occurred with either the G9SE or the configuration in which it is installed.

Solution

To appropriately resolve this issue, the indicator lights must first be interpreted to determine the cause.

The indicator lights on a G9SE unit are the same for the G9SE-201 and the G9SE-401, and appear as shown in the below image.

The indicator lights on a G9SE-221-T05 and G9SE-221-T30 are slightly different from the other models, and appear as shown in the below image.

Please follow the below questions to determine the cause of the issue, and checks to make to resolve the issue.

Decision Tree
What is the condition of the power indicator light?
  • Lit up / On
  • Not lit / Off
  • Blinking
  • Add Button
What is the condition of the IN1 and IN2 indicator lights?
  • One or both are blinking
  • Add Button
There is a mismatch between Safety inputs 1 and 2.

Remove power from the G9SE unit, then check the wiring from the safety input devices to the G9SE unit. 

Alternatively, check the inputs sequence of the safety input devices.

What is the condition of the OUT indicator light or lights?

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There is an issue with the power being supplied to the G9SE unit.
Check the power input to the unit.
What is the condition of the other indicator lights?

Note that combinations of the below conditions are possible, therefore care should be taken when analysing the potential faults.

  • The IN1 indicator light is blinking
  • The IN2 indicator light is blinking
  • The IN1 and IN2 indicator lights are lit / On
  • The IN1 and IN2 indicator lights are not lit / Off
  • The OUT indicator light is blinking
  • The OUT1 and OUT2 indicator lights are blinking
  • The OUT2 indicator light is blinking
  • All of the other indicator lights are blinking
  • All of the other indicator lights are not lit / Off
  • Add Button
There are two possible faults associated with this indicator light pattern.

1) Failures involving the wiring of safety input 1.

Resolve this issue by removing power from the G9SE unit, then check the wiring to terminals T11 and T12.

2) Failures of the parts of the circuits of safety input 1.

This fault requires replacement of the G9SE unit with a new unit.

There are two possible faults associated with this indicator light pattern.

1) Failures involving the wiring of safety input 2.

Resolve this issue by removing power from the G9SE unit, then check the wiring to terminals T21 and T22.

2) Failures of the parts of the circuits of safety input 2.

This fault requires replacement of the G9SE unit with a new unit.

If the safety inputs of the G9SE unit are in the ON state, these indicator lights indicate two possible faults.

1) Failures involving the wiring of the Feedback/Reset input.

Resolve this issue by removing power from the G9SE unit, then check the wiring to terminals T31, T32 and T33.

2) Failures of the parts of the circuits of the Feedback/Reset input.

This fault requires replacement of the G9SE unit with a new unit.

If the safety inputs of the G9SE unit are in the OFF state, these indicator lights indicate two possible faults.

1) Failures involving the wiring of the Feedback/Reset input.

Resolve this issue by removing power from the G9SE unit, then check the wiring to terminals T31, T32 and T33.

2) Failures of the parts of the circuits of the Feedback/Reset input.

This fault requires replacement of the G9SE unit with a new unit.

There is a failure of the parts or relays of the circuits of the Safety Output.

This issue requires replacement of the G9SE unit with a new unit.

This indicator light pattern can only occur on the G9SE-221-T05 and G9SE-221-T30 models.

There is a failure of the parts or relays of the circuits of the Safety Output.

This issue requires replacement of the G9SE unit with a new unit.

This indicator light pattern can only occur on the G9SE-221-T05 and G9SE-221-T30 models.

There is a mismatch of the two Off-Delay Time Preset Switches.

Remove power from the G9SE unit, and check both of the two Off-Delay Time Preset Switches. Both switches must be set to the same value.

Note that one switch is located on the front of the G9SE unit, near the indicator lights, while the other switch is located on the rear of the G9SE unit.

The supply voltage to the G9SE unit is outside of the rated value.

Remove power from the G9SE unit, and check the supply voltage. The rated supply voltage for the G9SE is 24 VDC, with a variance of -15% to +10%.

Note that while this translates to a voltage range of 20.4 VDC to 26.4 VDC, it is possible for the supply voltage to fluctuate due to external factors, so it is desirable for the value of the supply voltage to be as close to 24 VDC as possible.

There are two possible faults associated with this indicator light pattern.

1) Excessive electro-magnetic disturbance.

Resolve this issue by removing power to the G9SE unit, then check the level of electro-magnetic disturbance around the G9SE and the associated system connected to the unit.

2) Failures of parts of the internal circuits.

This issue requires replacement of the G9SE unit with a new unit.

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Another method of determining the fault is to consult the below tables.

If your G9SE unit is showing indicator light patterns that are not covered by this guide, please consult your local OMRON support for further assistance.

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