4 Fault Isolation
4.3 Fault Isolation Concepts
R688 HPM High-Performance Process Manager Service 347
December 2020 Honeywell
Table 62 IOP Box Soft Failure Error Codes
FTA 2 calibration procedure failed.
Secondary IOP has lost
synchronization.
If the primary IOP is in OK, resynch with the
START command. If the primary IOP is in IDLE,
resynch with the IDLE command.
AO or DO IOP write enable failure.
Replace the IOP at the earliest convenience.
IOP failure can result in indeterminate outputs.
Multiple input failure detected.
Redundancy diagnostic failure.
If an AO, replace the FTA’s plug-in module
after forcing IOP A to be the primary.
If an HLAI, replace the IOPs one at a time
following database synchronization.
Wrong hardware revision for IOP
redundancy
Replace the IOP with an IOP that supports
redundancy (proper hardware revision).
The DISOE Hardware FIFO
diagnostic failed. The PVs of all
points are set to BAD.
The DISOE Private RAM diagnostic
failed. The PVs of all points are set to
BAD.
The DISOE clock failed. The PVs of
all points are set to BAD.
The PV validation diagnostic failed.
The PVs of all points are set to BAD.
The DISOE SOE counter diagnostic
failed.
Replace the FTA when convenient.
Replace the FTA when convenient.
The DISOE State Machine diagnostic
failed. The PVs of all points are set to
BAD.