• If the mA output reading at the receiving device was significantly inaccurate, or if at
any step the reading was faulty, verify the wiring between the transmitter and the
remote device, and try again.
• If the discrete output reading is reversed, check the setting of Discrete Output Polarity.
10.12.5 Perform loop tests using the Field Communicator
A loop test is a way to verify that the transmitter and the remote device are
communicating properly. A loop test also helps you know whether you need to trim mA
outputs.
Prerequisites
Before performing a loop test, configure the channels for the transmitter inputs and
outputs that will be used in your application.
Follow appropriate procedures to ensure that loop testing will not interfere with existing
measurement and control loops.
Procedure
1. Test the mA output(s).
a. Choose Service Tools > Simulate > Simulate Outputs > mA Output Loop Test and select 4
mA.
b. Read the mA current at the receiving device and compare it to the transmitter
output.
The readings do not need to match exactly. If the values are slightly different,
you can correct the discrepancy by trimming the output.
c. Press OK.
d. Select 20 mA.
e. Read the mA current at the receiving device and compare it to the transmitter
output.
The readings do not need to match exactly. If the values are slightly different,
you can correct the discrepancy by trimming the output.
f. Press OK.
g. Choose End.
2. Test the frequency output(s).
Note
If the Weights & Measures application is enabled on the transmitter, it is not possible to
perform a loop test of the frequency output, even when the transmitter is unsecured.
a. Press Service Tools > Simulate > Simulate Outputs > Frequency Output Test, and choose
the frequency output level.
Troubleshooting
200 Micro Motion
®
Model 1700 Transmitters with Analog Outputs