Honeywell STT25D, Operator'S Manual

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Smart Temperature Transmitter STT250 – Operator Manual 21
SYMPTOM SFC MESSAGE/
DISPLAY
POSSIBLE CAUSE CURE
Incorrect
output signal
with
simulating
device " STATUS
CHECK = O.K. "
but does not
correspond to
value set by
simulating device
The most common error is
changing the sensor
wiring after probe type
selection or after power-
up. Check the
appropriate sensor
wiring and power
cycle when it is
correct.
Remember when
changing
configuration to first
connect sensor
wiring correctly,
then change
configuration.
" INVALID
REQUEST "
when
changing
LRV or URV
" INVALID
REQUEST "
If the LRV is changed, the
URV tries to change by the
same amount to maintain
the same SPAN. If this new
URV exceeds the URL
then this message
appears. Reduce the URV or
SPAN before
changing the LRV.
Non-critical
status
message,
without # sign " USER CORR
ACTIVE "
Transmitter has been
trimmed for particular
sensor range. This can be
done by keying in
LRV/URV, CORRECT,
ENTER with exact LRV
and URV input values to
enable improved accuracy
over the specifications. When performing a
Reset Correct
command or a
sensor type
change, the
transmitter will lose
this sensor
correction and fall
back to the original
factory calibration.
Remember that successful communications with the STT250 result in many useful
pieces of data. With the initial I.D. response, the user can confirm that the:
1. Transmitter is powered
2. Line resistance is correct
3. Wires run to the correct unit. If not, the unit connected can be identified by the
tag number.