Overview
The Allen-Bradley 1771-OFE1 is a four-channel isolated analog output module designed for PLC-5 controller platforms. This module provides selectable voltage ranges of ±10 VDC, 0–10 VDC, and +1 to +5 VDC, enabling precise control of analog devices in industrial automation systems. Each of its four channels is individually isolated, ensuring noise immunity and preventing cross-channel interference in demanding process environments.
Key Features
- Four individually isolated voltage output channels with ±10 VDC capability
- 12-bit resolution with 1.50 Ampere backplane current draw
- Converts digital values in binary or BCD format into precise voltage signals for actuators, position controllers, indicators, and data acquisition devices
- No external power supply required; operates from I/O chassis backplane with continuous diagnostics
- Range selection jumpers set individually for each channel according to desired output range
Technical Specifications
The module is built to integrate seamlessly with Allen-Bradley’s 1771 Universal I/O chassis architecture. The 1771-OFE1 uses block transfer programming for data transfer, with Write Block Transfer instructions moving data up to 13 words for DA conversion in one scan.
Typical Applications
Peripheral devices such as motor speed controllers, valve positioners, recorders, or signal converters can be connected to the output. Common uses include:
- Analog drive and motor speed control
- Process control and data logging systems
- Valve position feedback and control loops
- Sensor bridge and instrumentation interfacing
Compatibility & Replacements
Compatible With
- PLC-5 family controllers and processors
- Allen-Bradley Universal I/O Chassis models 1771-A1B, 1771-A2B, 1771-A3B, and 1771-A4B
- 1771 series I/O modules and accessories
- Block Transfer instruction sets (Studio 5000 offline; legacy PLC-5 APS online)
Replaces / Drop-In Replacement For
- 1771-OFE1 Series A and earlier revisions
- Other legacy PLC-5 analog output modules when voltage ranges align
Works With
- PLC-5 ladder logic programming
- Allen-Bradley APS (Allen-Bradley Programming Software)
- Studio 5000 (for documentation and offline reference)
- Block Transfer I/O instructions for data movement
- 1771-WC wiring arm and terminal connections
