Overview
The Allen-Bradley 1794-OF4I is a Flex I/O isolated analog output module designed for distributed industrial automation. This Series A unit provides four isolated output channels, supporting both voltage and current signal types to drive analog field devices such as proportional valves, motors, and instrumentation.
Key Features
- Four isolated analog output channels – each with independent signal conditioning
- Flexible output ranges: 4–20mA, 0–20mA (current); ±10V, 0–10V, ±5V, 0–5V (voltage)
- High accuracy: 0.1% full-scale accuracy at 25°C with ultra-low drift (0.0012%/°C voltage, 0.0025%/°C current)
- Factory calibrated with optional manual calibration capability
- DIN-rail and panel-mount compatible – integrates into compact enclosures
- Hot-swappable design – supports field replacement under backplane power (follow best practices for field-side power removal)
Technical Specifications
The module operates on 24VDC external power supply (19.2–31.2VDC rated range) and draws 5VDC / 50mA FlexBus power. Isolation voltage is 120V continuous, protecting plant networks from field-side faults. Output voltage accuracy is ±10V maximum with 0–750Ω resistive load capability; current output tolerates 32mA continuous maximum per channel with 3mA load maximum on voltage outputs. Power dissipation ranges from 4.0–4.6W depending on supply voltage. Dimensions (installed): 94 × 94 × 89mm; weight: approximately 2kg (4.4 lbs).
Typical Applications
- Distributed control for multi-axis motion and valve sequencing
- 4–20mA sensor loop control and analog device signaling
- Proportional flow/pressure valve drive in hydraulic and pneumatic systems
- Precision instrumentation output (scale, pressure transmitter feedback)
- HVAC and environmental control systems requiring isolated analog signals
Compatibility & Replacements
Compatible With
- Flex I/O terminal bases: 1794-TB2, 1794-TB3, 1794-TB3S, 1794-TB3T, 1794-TB3TS, 1794-TBN, 1794-TBNF
- All 1794 Flex I/O chassis and distributed adapters
- CompactLogix and ControlLogix processors via Flex I/O backplane
- Allen-Bradley FactoryTalk View and Studio 5000 (RSLogix 5000) platforms
Replaces / Drop-In Replacement For
The 1794-OF4I Series A is a direct replacement for identical earlier Series A units. Verify the keyswitch position (Position 4 for this module) when replacing units in existing installations.
Works With
- Studio 5000 and RSLogix 5000 programming platforms
- Allen-Bradley FactoryTalk Engineering and communication suites
- EtherNet/IP and Industrial Ethernet networks via Flex I/O gateway adapters
- Isolated analog loop protocols: 4–20mA, 0–20mA, 0–10VDC, ±10VDC standards
