Product Overview

The Allen-Bradley 1794-OF4I belongs to the Flex I/O product family. This isolated analog output module delivers precise current and voltage signals to field devices. The Allen-Bradley 1794-OF4I has 4 isolated output channels for flexible configuration. You can use the module with multiple Flex I/O terminal base units. The module mounts on DIN rail or directly to the enclosure sub-panel. The Allen-Bradley 1794-OF4I works with any available Flex I/O communication adapter.

Technical Specifications

The Allen-Bradley 1794-OF4I delivers high precision analog output control for Flex I/O systems. All parameters follow the official datasheet.

Output Specifications

• Number of outputs: 4 isolated channels

• Output current ranges: 4-20 mA and 0-20 mA (user-configurable)

• Output voltage ranges: ±10VDC, 0-10VDC, ±5VDC, 0-5VDC (user-configurable)

• Conversion type: Digital to Analog Converter (DAC)

• Resolution: 15 bits plus sign

Resolution Details

• Voltage resolution: 0.320 mV per count

• Current resolution: 0.656 μA per count

• The Allen-Bradley 1794-OF4I provides fine granularity for precise output control.

Update Rate & Response

• Update rate: 2.5 ms or 5.0 ms for all channels (configurable)

• Step response to 63% of full scale: < 25 microseconds

• The Allen-Bradley 1794-OF4I delivers fast response for dynamic control loops.

Output Load Specifications

• Current load on voltage output: 3 mA maximum

• Resistive load on voltage output: 0 to 750 Ω

• Voltage output until configuration: 0 Volts

• Current output until configuration: 0 mA

Accuracy & Drift

• Absolute accuracy at 25°C: 0.1% full scale for both voltage and current terminals

• Voltage accuracy drift: 0.0012% full scale per degree Celsius

• Current accuracy drift: 0.0025% full scale per degree Celsius

• Factory calibration: Included with manual calibration option

Overload Protection

• Maximum overload: 30V continuous OR 32 mA continuous

• Note: Overload applies to one channel at a time

Power Specifications

• External DC supply nominal: 24V DC

• External DC supply range: 19.2 to 31.2V DC (includes 5% AC ripple)

• External DC power supply current: 210 mA at 24V DC

• FlexBus voltage: 5V DC

• FlexBus current: 50 mA

• Maximum power dissipation at 31.2V DC: 4.7 Watts

• Maximum thermal dissipation at 31.2V DC: 16 BTU per hour

Isolation Specifications

• Isolation voltage (with 1794-TBN base): 250V continuous

• Isolation voltage (with other bases): 120V continuous

• The Allen-Bradley 1794-OF4I isolation depends on the selected terminal base.

Compatible Terminal Bases

The Allen-Bradley 1794-OF4I works with:

• 1794-TB2

• 1794-TB3

• 1794-TB3S

• 1794-TB3T

• 1794-TB3TS

• 1794-TBN

• 1794-TBT

• 1794-TBNF

Environmental Specifications

• Operating temperature: 0°C to 55°C (32°F to 131°F)

• Storage temperature: -40°C to 85°C (-40°F to 185°F)

• Vibration: 5g at 10 to 500 Hz

• Operating shock: 30g

Physical Specifications

• Dimensions: 3.7 x 2.6 x 3.7 inches

• Mounting: DIN rail or panel mount

• Enclosure style: Open enclosure

• UPC: 10612598171580

Hazardous Location Approval

• The Allen-Bradley 1794-OF4I is approved for use in hazardous locations.

Installation Guide

Follow these steps to install the Allen-Bradley 1794-OF4I correctly.

1. Mount the terminal base on DIN rail or directly on the enclosure sub-panel.

2. Select a compatible base from the 1794-TB2, TB3, TB3S, TB3T, TB3TS, or TBN series.

3. Wire field actuators to the terminal base following output ranges.

4. Insert the 1794-OF4I into the terminal base assembly.

5. Connect external 24V DC power at 19.2 to 31.2V range.

6. Configure output ranges for current or voltage signals as needed.

7. Set the update rate to 2.5 ms or 5.0 ms on the Allen-Bradley 1794-OF4I.

Packing List

This package for the Allen-Bradley 1794-OF4I includes the following items.

• Allen-Bradley 1794-OF4I isolated analog output module (one unit)

• Product documentation and installation guide

• Anti-static protective bag

Frequently Asked Questions (FAQ)

1. How many output channels does the 1794-OF4I have?
The Allen-Bradley 1794-OF4I has 4 isolated analog output channels. Each channel is user-configurable for current or voltage signals.

2. What output ranges does the 1794-OF4I support?
The Allen-Bradley 1794-OF4I supports 4-20mA, 0-20mA, ±10VDC, 0-10VDC, ±5VDC, and 0-5VDC. All ranges are user-configurable for application flexibility.

3. What is the resolution of the 1794-OF4I?
The resolution is 15 bits plus sign for the Allen-Bradley 1794-OF4I. Voltage resolution is 0.320 mV per count and current resolution is 0.656 μA per count.

4. What is the update rate for the 1794-OF4I?
The update rate is selectable at 2.5 ms or 5.0 ms for all channels. The Allen-Bradley 1794-OF4I has a step response of <25 microseconds to 63% of full scale.

5. What terminal bases work with the 1794-OF4I?
The Allen-Bradley 1794-OF4I works with 1794-TB2, TB3, TB3S, TB3T, TB3TS, TBN, TBT, and TBNF. Isolation voltage is 250V continuous with 1794-TBN or 120V continuous with other bases.