AW T4 20 |
U N I V ER S A L 4 - W I R E , D UA L- I N P U T T R A N SM I T T ER | O I/AW T4 2 0 - EN R E V. B
83
16 Troubleshooting
Diagnostic messages
The transmitter is programmed to display NAMUR 107
diagnostic icons and messages to provide information on
servicing requirements and any other conditions that develop
during operation.
All diagnostic messages displayed on the transmitter are added
to the transmitter’s
Audit Log
. The following tables show icon
types, diagnostic messages and possible causes/suggested
remedial action.
Failure
Check
function
Out of
specification
Maintenance
required
Process value
invalid due to
malfunction in
sensor or
transmitter
Process value
temporarily invalid
due to specified
action
Process value
unreliable due to
sensor operating
outside specified
range/limits
Process value valid
– intervention
required to correct
operational
conditions
Table 7 NAMUR 107 diagnostic icons
AWT420 transmitter diagnostics
NAMUR
icon
Diagnostic
message
Cause
Recovery action
S(n):
Comms Error
Communications between transmitter and
sensor have been lost.
The likely cause is a poor/broken connection
between the sensor/sensor module and the
transmitter or a terminal fault in the sensor.
1. Inspect the transmitter and sensors ensuring that EZLink/Sensor
module is fitted correctly in the transmitter.
2. For EZLink sensors, ensure the sensor is connected and the wiring is
intact between the transmitter and the sensor housing.
3. Perform a power cycle on the transmitter.
4. If
Comms Error
persists, contact local service organization.
AO(n):
Out of Range
The source assigned to the analog output is
outside its programmed engineering range.
The output is fixed at its electrical limits
of 0 mA (under range) or 22 mA (overrange)
until the source is within range.
Check the configuration of the analog output, ensuring that the
Source,
Eng. High
and
Eng. Low
values are set according to the requirements and
adjust if necessary.
Memory Write
Error
Transmitter configuration data is corrupt, or
the transmitter’s non-volatile memory is faulty.
The device setup may be affected and changes
to configuration may not be maintained after
power cycle.
Cycle power to the transmitter. If
Memory Write Error
persists:
1. Check all configuration parameters and correct any errors.
2. Backup configuration to SD card
3. Reset to defaults via the bootloader.
4. Reload configuration from SD card
5. If
Memory Write Error
persists, contact local service organization
S(n):
PV Out of Range
The primary variable from the sensor is outside
the range specified in Sensor Setup.
1. Check the process and adjust if necessary.
2. If the measured value is within the intended range of the process,
adjust the
Range High
and
Range Low
in the
Sensor Setup
menu
– see page <?>.
Simulation
Active
Transmitter is in simulation mode: signal
values are generated internally and do not
reflect process conditions.
Contact local service organization.
Inf. pH Invalid
The calculated (inferred) pH value is outside
the accurate range for the specified solution.
For Calculation Type = NH3/NH3 and NaCl the
accurate range is 7.00 to 10.00 pH.
For Calculation Type = NaOH/NaOH and NaCl
the accurate range is 7.00 to 11.00 pH.
Check the process and the measured conductivity before, and after,
the cation chamber.
Adjust the process if necessary.
Ensure that the cell constants and temperature compensation are set
correctly for each sensor.
Before Cat.
High
Conductivity measured before the cation
exchange chamber is above the user set limit.
Inferred pH reading may be inaccurate.
Check the process and make any necessary adjustments.
Ensure that the before cation sensor has been correctly setup and
if necessary adjust the limit.
After Cat.
High
Conductivity measured after the cation
exchange chamber is above the user set limit.
Inferred pH reading may be inaccurate.
Check the process and make any necessary adjustments.
Ensure that the after cation sensor has been correctly setup and
if necessary adjust the limit.
