Perform Loop Tests - Emerson Micro Motion 9739 MVD Configuration And Use Manual

Troubleshooting
June 2019

10.16 Perform loop tests

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
• Follow appropriate procedures to ensure that loop testing will not interfere with existing measurement
and control loops.
10.16.1 Perform loop tests using the display
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) 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.
b) At the transmitter, activate Select.
c) Scroll to and select a high value, e.g., 20 mA.
Dots traverse the display while the output is fixed.
d) 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.
e) At the transmitter, activate Select.
2. Test the Frequency Output(s).
a) Choose OFFLINE MAINT → SIM → FO SIM, and select the Frequency Output value.
The Frequency Output can be set to 1, 10, or 15 kHz.
Dots traverse the display while the output is fixed.
b) Read the frequency signal at the receiving device and compare it to the transmitter output.
c) At the transmitter, activate Select.
3. Test the Discrete Output(s).
a) Choose OFFLINE MAINT → SIM → DO SIM, and select SET ON.
Dots traverse the display while the output is fixed.
144
Configuration and Use Manual
MMI-20016855
Micro Motion 9739 MVD Transmitters