Omron G9SX Manual page 16

When indicators other than the ERR indicator blink, check and take necessary actions referring to the following table.
ERR Other
indicator indicators
T1 Mismatch between input 1
and input 2.
T2
Off Blink
(Expansion Unit)
ERR Other
indicator indicators
--- Fault involved with safety
relay outputs of Expansion
Light up
Units
16
Flexible Safety Unit
Fault Expected cause of the fault
The input status between input 1 and input
2 is different, due to contact failure or a
short circuit of safety input device(s) or a
wiring fault.
Fault Expected cause of the faults
1) Welding of relay contacts
2) Failure of the internal circuit
G9SX
Check points and measures to take
Check the wiring from safety input devices to the
G9SX. Or check the input sequence of safety
input devices. After removing the fault, turn both
safety inputs to the OFF state.
Check points and measures to take
Replace with a new product.