
Point Unhealthy Troubleshooting (continued)
Mode
Possible Cause
Solution
CurrentOutput
The commanded output is beyond the range of
the output.
Verify that the commanded output is within the range of the output.
CurrentOutput
There is a field wiring problem
Check the field wiring and device.
CurrentOutput
There is an open loop or too much resistance in
the loop.
Confirm the correct I/O pack 28 V input power. Check the field wiring and
device.
CurrentOutput
The I/O pack has failed.
Replace the I/O pack.
CurrentOutput
The terminal board has failed.
Replace the terminal board.
RTD
RTD wiring/cabling open or high impedance.
Check the field wiring and connections to indicated RTD input channel.
RTD
Open on connections to the terminal board.
Check the field wiring and field device.
RTD
RTD device failed.
Replace the RTD device.
RTD
YUAA module internal hardware problem.
Replace the I/O pack.
RTD
Current source on YUAA for RTD faulty or
measurement device failed.
Replace the I/O pack. Replace the field device.
RTD
Wrong type of RTD configured or selected by
default.
From the ToolboxST application, modify the YUAA I/O pack to correct the
configuration.
RTD
High-resistance values created by high voltage
and/or low current.
Check the field wiring and field device.
Thermocouple
Thermocouple millivolt input exceeds the limits
of the YUAA hardware.
Check field wiring, including shields. Measure incoming mV signal and
verify that it is within the specified thermocouple range. Check installation
of the I/O pack on the terminal board. This problem is usually not an I/O
pack or terminal board failure if other thermocouples are working correctly.
Verify that the installed type of thermocouple device matches the
configuration found in the ToolboxST application. Replace the field device.
Thermocouple
Cold junction input to the analog-to-digital
converter exceeded the limits of the converter. If
a cold junctions fails, the CJ_Backup value is
used.
Check installation of the I/O pack on the terminal board. If local CJ, replace
the terminal board.
Thermocouple
Thermocouple mV input exceeded range of
linearization (lookup) table for this TC type.
Refer to documentation for specified
thermocouple ranges.
Check field wiring, including shields. Measure incoming mV signal and
verify that it is within the specified thermocouple range. Check installation
of the I/O pack on the terminal board. Note: The problem is usually not an
I/O pack or terminal board failure if other thermocouples are working
correctly. Verify that the installed type of thermocouple device matches the
configuration found in the ToolboxST application. Replace the field device.
Thermocouple
Thermocouple configured as wrong type.
Verify that the installed type of thermocouple device matches the
configuration found in the ToolboxST application.
Thermocouple
Board detected a thermocouple open
Check field wiring, including shields. Replace the field device.
Thermocouple
Stray voltage or noise caused the input to
exceed its range.
Check field wiring, including shields. Replace the field device.
YUAA Universal I/O Modules
GEH-6855_Vol_II System Guide 217
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