16 Troubleshooting; Diagnostic Messages; Awt420 Transmitter Diagnostics - ABB AWT420 Operating Instruction

AW T4 2 0 | U N I V E R S A L 4 - W I R E , D U A L- I N P U T T R A N S M I T T E R | O I/A W T4 2 0 - E N R E V. B

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.

AWT420 transmitter diagnostics

NAMUR Diagnostic
icon message
S(n):
Comms Error
AO(n):
Out of Range
Memory Write
Error
S(n):
PV Out of Range
Simulation
Active
Inf. pH Invalid
Before Cat.
High
After Cat.
High
Cause
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.
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.
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.
The primary variable from the sensor is outside
the range specified in Sensor Setup.
Transmitter is in simulation mode: signal
values are generated internally and do not
reflect process conditions.
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.
Conductivity measured before the cation
exchange chamber is above the user set limit.
Inferred pH reading may be inaccurate.
Conductivity measured after the cation
exchange chamber is above the user set limit.
Inferred pH reading may be inaccurate.
Failure Check
function
Process value Process value
invalid due to temporarily invalid
malfunction in due to specified
sensor or action
transmitter
Table 7 NAMUR 107 diagnostic icons
Recovery action
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.
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.
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
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 <?>.
Contact local service organization.
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.
Check the process and make any necessary adjustments.
Ensure that the before cation sensor has been correctly setup and
if necessary adjust the limit.
Check the process and make any necessary adjustments.
Ensure that the after cation sensor has been correctly setup and
if necessary adjust the limit.
Out of Maintenance
specification required
Process value Process value valid
unreliable due to – intervention
sensor operating required to correct
outside specified operational
range/limits conditions
83