Moore HIMHART2AO24DC HART Interface Module

Description

Key Technical Specifications

The module can retrieve HART dynamic variables and map selected variables to its two analog outputs. Public technical listings also describe selectable fail-safe behavior, including fail-high, fail-low, hold-last-value, and hold-then-fail modes.

Product Introduction

The Moore Industries HIMHART2AO24DC is a two-channel HART interface module that extracts process variables from a HART-enabled field instrument and converts them into independent isolated 4–20 mA signals. This allows a DCS, PLC, recorder, or monitoring system to receive HART variables through conventional analog inputs.

The module is useful when an existing control system lacks native HART variable handling. Each output can be configured and scaled independently, while galvanic isolation separates the field-side HART circuit from the analog outputs and power circuit.

HIMHART2AO24DC

HIMHART2AO24DC

Installation & Configuration Guide

Stage 1 — Pre-Installation Preparation

Estimated time: 15–30 minutes

1. Confirm the replacement marking is HIMHART2AO24DC.
2. Verify the system requires two 4–20 mA outputs derived from HART variables.
3. Record the existing configuration, output scaling, HART device address, and selected process variables.
4. Photograph all terminal wiring before removal.
5. Confirm the available power supply is 24 V DC.
6. Check the DCS/PLC analog-input load before commissioning.
7. Obtain the existing configuration file if the original module is still accessible.

⚠️ Do not assume that a replacement module has the same HART variable mapping as the removed unit.

Stage 2 — Removing the Existing Module

Estimated time: 10–15 minutes

1. Apply the site’s electrical isolation and LOTO procedure.
2. Verify that the module is de-energized.
3. Label the HART, analog-output, and power conductors.
4. Disconnect the wiring without stressing the terminal blocks.
5. Release the module from the DIN rail.
6. Inspect the wiring and cabinet terminals for corrosion, loose conductors, or damaged insulation.

Stage 3 — Installing the New Module

Estimated time: 15–25 minutes

1. Mount the HIMHART2AO24DC securely on the DIN rail.
2. Connect the 24 V DC supply with correct polarity.
3. Connect the HART field-device circuit according to the approved loop drawing.
4. Connect analog Output 1 and Output 2 to the corresponding DCS/PLC channels.
5. Verify shield and grounding arrangements against the plant wiring standard.
6. Use the appropriate PC configuration interface to configure the HART variables and output scaling.
7. Set the required fail-safe behavior for each output.

⚠️ Verify the selected HART variable before putting either analog output into automatic control.

Stage 4 — Power-On & Testing

Estimated time: 20–40 minutes

1. Energize the 24 V DC supply.
2. Confirm the module powers up normally.
3. Establish HART communication with the field instrument.
4. Verify the instrument’s primary, secondary, tertiary, or quaternary variables as applicable.
5. Confirm Output 1 corresponds to the intended process variable.
6. Repeat the verification for Output 2.
7. Check the actual 4–20 mA values at the DCS/PLC terminals.
8. Test the configured fault response under an approved test condition.
9. Record the final HART mapping and analog scaling.

⚠️ Do not force a HART fault or disconnect a live process instrument unless the site’s commissioning procedure explicitly permits the test.

FAQ

1. What is the HIMHART2AO24DC used for?

It extracts digital process variables from a HART-enabled field instrument and provides two independent 4–20 mA outputs for conventional DCS, PLC, recorder, or monitoring inputs.

2. How many analog outputs does it provide?

The HIMHART2AO24DC provides two independent 4–20 mA analog outputs. The outputs can be assigned and scaled for selected HART variables.

3. Does it replace a HART transmitter?

No. It interfaces with an existing HART field device. The field transmitter remains responsible for measuring the process variable; the extracts HART data and converts selected variables into analog outputs.

4. What power supply does the require?

Public technical listings specify 24 V DC, 4-wire operation. Verify the actual nameplate and applicable Moore Industries documentation before energizing a replacement module.

5. What is the maximum analog-output load?

The documented maximum load is 1,100 Ω per output. The actual permissible load should be checked against the complete loop voltage budget and DCS/PLC input arrangement.

6. Can the module retain or reproduce the original HART configuration?

The module is configurable, but a replacement should not be assumed to contain the removed unit’s configuration. Record the HART address, variable assignments, scaling, and fault behavior before replacement whenever possible.

7. What should I verify before ordering a replacement?

Confirm the complete part number , power requirement, HART loop arrangement, two analog-output configuration, output scaling, and required fail-safe behavior. Also verify whether the existing installation uses any hazardous-area option or certification requirement; the publicly indexed specifications do not by themselves establish the certification of every individual installation.