Table 34: Summary Of Function Blocks Critical Faults - Honeywell ST700 User Manual

Table 34 summarizes the conditions that could cause a critical fault in the transmitter along with
recommended actions to correct the fault.
Problem/Fault
AI block is
executing, but
status of output is:
Bad:[alarm status]:
sensor failure
AI block is
executing, but
status of output is:
Bad::[alarm status]:
device failure
Revision 2.0 FOUNDATION Fieldbus ST 700 Pressure Transmitter User's Guide

Table 34: Summary of Function blocks Critical Faults

Probable Cause
Transducer board generates:
a) Meter body fault.
b) Characterization PROM
fault.
c) Electronics fault.
d) Suspect input.
e) Sensor over temperature -
sensor temperature is
greater than 125 °C (257
°F).
Transducer board has stopped
communicating with the stack
board.
Recommended Action
a) and b) Write "4" or
"restart processor" to
RESTART parameter
of resource block. If
failure still exists,
replace the meter
body.
c) and d) Write "4" or
"restart processor" to
RESTART parameter
of resource block. If
failure still exists,
replace the transmitter
electronics module.
e) Reduce temperature
at sensor. Take steps
to insulate meter body
from temperature
source.
Write "4" "or "restart
processor" to
RESTART parameter
of resource block. If
failure is still present,
replace transmitter
electronics module.
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