Product Overview

The Allen-Bradley 1771-OFE2 acts as a high-precision digital-to-analog converter within the legacy PLC-5 control system architecture. This module converts digital values from the PLC processor into highly accurate analog current or voltage signals to manage field devices. It serves as a critical link between central processing racks and variable field instruments like control valves, actuators, and motor drives. We supply this product as a 100% brand new, original unit to secure long-term operational uptime for existing factory automation infrastructures.

Technical Specifications

This module interfaces directly with standard 1771 I/O chassis slots and relies on the following verified engineering parameters:

• Product Type: Analog Output Module

• System Compatibility: PLC-5 Controllers / 1771 I/O Chassis

• Analog Outputs: 4 Points (Configurable for 2 Active Channels)

• Signal Ranges: 4 to 20 mA Current Loop / +/-10 VDC Voltage

• DAC Resolution: 12-Bit Binary

• Module Accuracy: +/-0.1% of Full Scale

• Output Load Impedance (Voltage): Greater than or equal to 1 kOhm

• Output Load Impedance (Current): Less than or equal to 750 Ohm

• Electrical Isolation: Optical/Galvanic Isolation between Channels and Backplane

• Signal Response Time: Less than 1 ms

• Backplane Current Draw: 1.2 A to 1.4 A at 5 VDC

• Operating Temperature: 0 to 60 degrees Celsius

• Storage Temperature: -40 to 85 degrees Celsius

• Relative Humidity: 5% to 95% Non-condensing

• Physical Compliance: UL, CSA, and CE Compliant

Engineering Advantages

The 1771-OFE2 solves distinct electrical and environmental challenges on the factory floor through targeted hardware design choices:

• Eliminating Ground Loops: Industrial plants feature long cable runs that generate dangerous ground potential differences. This module integrates robust optical galvanic isolation between the output channels and the backplane logic. This barrier blocks high-voltage transients, prevents ground loop noise from corrupting PLC registers, and safeguards the central PLC-5 processor rack.

• Overcoming Signal Interference: High-power motor drives and switchgear create extreme electromagnetic interference (EMI) in modern factory automation environments. The 12-bit resolution and stable internal circuitry of the 1771-OFE2 generate clean, steady 4-20mA current signals that resist long-distance environmental EMI noise, ensuring precise positioning of downstream control valves.

• Rapid Diagnostic Troubleshooting: Unplanned downtime costs industrial facilities thousands of dollars per hour. The front panel incorporates active LED diagnostic indicators that display channel status at a glance. Field technicians can instantly isolate whether a signal loss stems from internal module faults or external field wiring breaks without deploying specialized metering tools.

FAQs

• Does this 1771-OFE2 module arrive in 100% brand new condition? Yes. We ship this product as a 100% brand new, original unit in its original packaging. It has never seen service on a factory floor and contains zero refurbished components.

• Can the module drive both voltage and current loops simultaneously? The module hardware design allows engineers to configure channels for either current (4-20 mA) or voltage (+/-10 VDC) ranges. You must match the external field wiring terminals and PLC configuration blocks to the specific signal type required by your actuator or drive.

• Does the 1771-OFE2 require an independent external power supply? The module draws its primary operating power (up to 1.4 A) directly from the 1771 I/O chassis backplane power supply. However, you must ensure your existing chassis power supply has sufficient headroom to support this current draw alongside your other installed PLC-5 modules.