ABB RET650 2.1 IEC Commissioning Manual page 47

1MRK 504 160-UEN -
Transformer protection RET650 2.1 IEC
Commissioning manual
Each logical I/O module has an error flag that indicates signal or module failure. The
error flag is also set when the physical I/O module of the correct type is not detected
in the connected slot.
Configuring the IED and changing settings
Section 5
41