Overview
Allen-Bradley 1771-OFE2 is an intelligent analog output module that converts binary or four-digit BCD values to analog current signals. The module features four individually isolated differential outputs rated at 4-20mA, making it suitable for proportional valve control, analog instrumentation, and process feedback loops in PLC-5 automation systems.
Key Features
- Four isolated outputs: Controls four differential voltage or current outputs, each with 1000V isolation for noise immunity
- 12-bit digital resolution: 12-bit binary precision for accurate signal reproduction
- 4-20mA current range: 4 to 20mA output per channel; maximum 1200 ohms load resistance per channel
- Configurable test mode: Test Mode Output jumper controls the magnitude of the outputs if the module should receive a reset condition
- Block transfer intelligence: Handles binary-to-analog and BCD-to-analog conversion automatically
- Single-slot design: Fits any slot in 1771 I/O chassis (except leftmost Remote I/O Adapter slot)
Technical Specifications
- Number of Outputs: Four (4) analog current channels
- Output Type: 4-20mA isolated differential
- Digital Resolution: 12-bit binary
- Output Current Range: 4-20mA per channel
- Maximum Load Resistance: 1200 ohms per channel
- Channel Isolation: 1000V differential
- Operating Temperature: 0–60°C (32–140°F)
- Power Dissipation: 7.9 watts
- Module Width: Single slot (1771 chassis)
- Backplane Power Draw: 1.50A
- Field Wiring Arm: Allen-Bradley 1771-WC (included)
- Certifications: CE, CSA, UL, C-TICK, MARINE
- Weight: 2.11 lbs
Typical Applications
The 1771-OFE2 serves process control, proportional solenoid valve actuation, stepper motor speed regulation, proportional pump control, analog pressure transmitter interfaces, and feedback-loop stabilization in legacy PLC-5 systems. It is also used in test equipment, hydraulic proportioning systems, and analog instrumentation requiring sub-second response times and minimal signal drift.
Compatibility & Replacements
Compatible With
- Allen-Bradley Universal I/O Chassis, 1771-A1B, 1771-A2B, 1771-A3B, or 1771-A4B
- All 1771 series I/O chassis variants
- PLC-5 control systems via standard block transfer programming
- RSLogix 5 and Studio 5000 (legacy mode) software
- DH+ and ETHERNET/IP networks through remote I/O adapters
Replaces / Drop-In Replacement For
- 1771-OFE1 (voltage output variant, not a direct replacement but same slot and chassis compatibility)
- Original 1771-OFE current versions with full backward compatibility
- Verify compatibility with your original system documentation before substitution
Works With
- RSLogix 5 programming software for PLC-5 ladder logic
- Studio 5000 (legacy 1771 module support)
- Allen-Bradley block transfer instructions (MSG function blocks)
- 1771-WC field wiring arm and screw-terminal connectors
- Proportional solenoid valves, variable frequency drives, servo amplifiers, and process controllers accepting 4-20mA setpoint signals
