Ams trex™ Device Communicator

5.14
Troubleshooting Fieldbus Diagnostics
If you see a measurement labeled 
BAD
or 
CHECK
, tap 
Details
to view the values for each
measurement. Press and hold a measurement value on the screen to view Help that
describes overview or troubleshooting information. You can also access the Help menu by
holding the checkmark button on the keypad when a measurement value is selected.
Note
To prevent inaccurate 
BAD
or 
CHECK
readings, review the measurement criteria in the
Settings
, and set the minimum and maximum values to ensure they are appropriate for
your installation.
Fieldbus Diagnostics application
User Guide
September 2021
174
User Guide

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Figure 5-11: Help text example
DC voltage measurement
Possible cause
Action
Lower than expected
The power supply's voltage
setting may be set too low.
Verify the power supply's
voltage setting is correct. If
necessary, increase the power
supply voltage.
An unexpected voltage drop
may be due to a damaged cable,
corrosion in the terminals, low
impedance to ground, water in
the device terminals, or loose
connections.
Measure the voltage at several
points on the fieldbus segment
to determine the location of the
unexpected voltage drop. Start
at the power supply and
continue toward the original
measurement point where the
voltage was measured low.
Higher than expected
There may be more than one
voltage source on the fieldbus
segment.
Ensure there is only one voltage
source.
The power supply's voltage
setting may be set too high.
Verify the power supply's
voltage setting is correct. If
necessary, decrease the power
supply voltage.