1794-OF8IH Allen-Bradley Flex IO HART Output Module

Product Overview

The 1794-OF8IH is an isolated analog output HART module from Rockwell Automation. It belongs to the Flex I/O series. This module provides eight isolated outputs. You can configure them for 0-20 mA or 4-20 mA signals. Each channel offers 16-bit resolution. This module supports HART communication for smart devices.

This module does not require external power. It draws power from the FlexBus. The FlexBus current is 80 mA at 5V DC. Maximum power dissipation is 5.0 W at 24V DC. Thermal dissipation is 17.06 BTU/hr at 24V DC. The module has a dedicated HART data register. That register is a 6 WORD register. It contains device fields, HART communication, loop status, and primary value.

Application Scenarios

Use the 1794-OF8IH in industrial automation systems. It is ideal for process control where HART protocol is needed. You can connect it to actuators, valves, and analog output devices. The module operates in harsh environments. It works from 32 to 131 degrees Fahrenheit. The module detects lead breakages. It has alarms for overrange and underrange currents.

Technical Specifications

• Number of outputs: 8 isolated
• Output signals: 0-20 mA, 4-20 mA
• Module resolution: 16-bit unipolar
• Conversion method: 16-bit digital to analog converter
• Conversion rate: 10 ms
• Data formats: Engineering Units, Percent of Full Scale, RAW/Proportional Count
• Terminal bases: 1794-TB3, 1794-TB3S
• Keyswitch position: 4
• Pass-through message support: Yes, with 1 or 2 connections
• Settling time: 70 ms
• Maximum power dissipation: 5.0 W @ 24V DC
• Thermal dissipation: 17.06 BTU/hr @ 24V DC
• FlexBus current: 80 mA @ 5V DC
• Operating temperature: 32 to 131 degrees Fahrenheit

Installation & Maintenance Guide

Install the module on a compatible terminal base. Align the keyswitch to position 4. Lock the module by rotating the keyswitch. Use the correct wiring for your terminal base type. No jumper or switch settings are needed. Rockwell Automation calibrates this module at the factory. For maintenance, keep the module clean and dry. Check connections regularly. The module supports pass-through messages to HART devices.

Packing List

• 1x 1794-OF8IH output module
• 1x installation manual

Shipping is via FedEx, UPS, or DHL.