Overview
Allen-Bradley 1771-OFE2 Analog Output Module
The Allen-Bradley 1771-OFE2 is an intelligent analog output module engineered for PLC-5 control systems. This module has a digital resolution of 12-bit binary. It features Four (4) individually isolated analog output channels that delivers 4-20 mA output current signal. The 1771-OFE2 is installed to any 1771 I/O chassis. It can serve as local and remote I/O module of a PLC 5 controller.
Key Features
- The 1771-OFE2 module has 4 output channels with isolation of 1000 Volt individually-isolated differential outputs.
- It requires a power of 1.4A at 5 Volts which is supplied from the I/O chassis backplane, thus no external power supply is needed.
- This module is typically used for controlling Final Control Elements (FCE) such as Variable Frequency Drives (VFD), Dampers, Louvers, Valves and other equipment and devices.
- It may also be used to implement the output of a Proportional + Integral + Derivative (PID) controller to implement automatic control of an analog loop.
- It occupies a single slot of the chassis and uses the 1771-WC field Wiring arm.
Technical Specifications
- Output Range: 4–20 mA (fixed range, live zero design)
- Each channels has rated isolation of 850 VDC for 1 Second while the Digital to Analog Converter (DAC) settling time is maximum of 0.8 ms.
- It has backplane current draw of 1.50 Amperes, power dissipation of 7.9 Watts, Thermal Dissipation of 26.9 BTU/hr and adjacent slot power maximum dissipation of 10 Watts.
- The output specifications for the current ranges dictate a maximum of 1200 ohms per channel of load resistance.
- When wiring output devices to the channels of this analog output module, use 12 Gauge stranded or solid wire with insulation thickness of 3/64 inch or 1.2 mm. Recommended cable is Belden 8761.
- During installation to the chassis, ensure that module keying is set at 10 and 12 / 26 and 28.
Typical Applications
This module is typically used for controlling Final Control Elements (FCE) such as Variable Frequency Drives (VFD), Dampers, Louvers, Valves and other equipment and devices. It may also be used to implement the output of a Proportional + Integral + Derivative (PID) controller to implement automatic control of an analog loop. Additionally, this module may also be used to transmit signals to measuring, receiving and recording elements such as Signal Isolators, signal converters, panel meters, data loggers and other similar instruments.
Compatibility & Replacements
Compatible With
- Allen-Bradley PLC-5 controllers
- 1771 I/O chassis (1771-A1B, 1771-A2B, 1771-A3B, 1771-A4B)
- 1771-WC field wiring arm
- Block Transfer mode operation in PLC-5 ladder logic
Replaces / Drop-In Replacement For
The 1771-OFE2 is a legacy module discontinued by Rockwell Automation as of March 4, 2021, with no planned direct replacement. For new installations, consult with your system integrator regarding modern ControlLogix or CompactLogix analog output options. Verify compatibility with your system integrator before ordering.
Works With
- Allen-Bradley PLC-5 programming software and ladder logic editors
- 1771 I/O chassis communication protocol
- Binary and BCD data scaling formats
- Block Transfer instruction set in PLC-5
