Emerson Micro Motion 5700 Configuration And Use Manual page 289

Configuration and Use Manual
MMI-20025166
• A Field Communicator
• A voltmeter
• Optional: The HART Application Guide, available at
Procedure
1. Verify the HART address.
Tip
The default HART address is 0. This is the recommended value unless the device is in a multidrop
network.
2. If the primary mA output is producing a fixed value of 4 mA, ensure that mA Output Action (Loop
Current Mode) is enabled.
For all HART addresses except 0, mA Output Action must be enabled to allow the primary mA output
to report process data.
3. Refer to the wiring diagrams in the installation manual and verify that the primary mA output is
correctly wired for HART support.
4. Ensure that the output is powered.
5. Check for electrical problems at the transmitter terminals.
a) Disconnect the primary mA output wires from the transmitter's MAO1 terminals.
b) Install a 250–1000 Ω resistor across the MAO1 terminals.
c) Check the voltage drop across the resistor.
For a 250 Ω resistor, 4–20 mA = 1–5 VDC. If the voltage drop is less than 1 VDC, add resistance
to achieve a voltage drop within the required range.
d) Connect a Field Communicator directly across the resistor and attempt to communicate (poll).
If this test fails, the transmitter may need service. Contact customer service.
6. Check for electrical problems at the transmitter terminals.
a) Disconnect the primary mA output wires from the transmitter's MAO1 terminals.
b) Wire and power the MAO1 terminals as shown in the following figure.
Configuration and Use Manual
www.hartcomm.org
Troubleshooting
March 2019
289