A-B 1771-OFE2 Analog Output Module

Allen-Bradley 1771-OFE2 Analog Output Module

 

 

The Allen-Bradley 1771-OFE2 is an analog output module used in the PLC-5 / 1771 I/O system. It converts PLC digital values into analog current signals (typically 4–20 mA) used to control field devices such as valves, actuators, drives, and process instruments.

It is a high-precision process control output module designed for industrial automation systems.

Key Specifications

• Model: 1771-OFE2
• Brand: Allen-Bradley (Rockwell Automation)
• Series: PLC-5 / 1771 I/O system
• Type: Analog Output Module
• Output Channels: 4 isolated analog outputs
• Signal Type:
  • 4–20 mA current output (primary)
  • Some configurations support voltage via system settings
• Resolution: 12-bit D/A conversion
• Isolation: Channel-to-channel isolation (~1000V)
• Mounting: 1771 chassis (1 slot)
• Wiring: 1771 removable wiring arm
• Programming Method: Block transfer (BTW/BTR with PLC-5 CPU)

What it does (simple explanation)

PLC CPU (1785 series)
↓
Digital output values
↓
1771-OFE2 Analog Output Module
↓
4–20 mA signal output
↓
Valve / actuator / VFD / instrument

It is used when the PLC needs to send smooth analog control signals instead of ON/OFF signals.

Main Functions

• Converts PLC digital data → analog current signals
• Controls valves, dampers, actuators
• Sends setpoints to VFDs or process controllers
• Provides stable analog output for process loops
• Supports multiple independent output channels
• Works with PLC-5 block transfer instructions

Key Features

• 4 fully isolated analog output channels
• High accuracy 12-bit conversion
• Industrial noise immunity design
• Supports 4–20 mA process standard (industry common)
• Fault detection and diagnostic capability
• Designed for continuous industrial process control

Applications

• Flow control valves
• Pressure control systems
• Temperature control loops
• VFD speed reference (analog speed command)
• Chemical process control
• Oil & gas automation systems
• Water treatment plants