Product Overview

The Allen-Bradley 1771-OW is a high-reliability relay contact output module designed for the legacy PLC-5 Universal I/O chassis. This module features eight independent output channels, strategically arranged into four isolated groups of two outputs each. This grouping allows for the simultaneous control of multiple circuits operating at different voltage levels and phases within a single module.

Engineered for maximum versatility, the 1771-OW allows users to select between Normally Open (N.O.) and Normally Closed (N.C.) contact states for each individual channel via internal jumpers. This hardware-level configurability makes it an essential component for fail-safe logic and complex switching requirements in heavy-duty industrial automation.

Technical Specifications

• Manufacturer: Allen-Bradley / Rockwell Automation

• Model Number: 1771-OW

• Product Series: PLC-5 (1771 I/O)

• Output Type: Selectable Relay Contact (Electromechanical)

• Number of Outputs: 8 Channels (4 isolated groups)

• Contact State: User-selectable (Normally Open or Normally Closed)

• Voltage Range (AC): 24V to 138V AC (Resistive)

• Voltage Range (DC): 24V to 125V DC

• Continuous Current: 1.0A per channel (max 8.0A per module)

• Backplane Current Load: 700mA

• Power Dissipation: 4.1W (max)

• Operating Temperature: 0 to 60 °C (32 to 140 °F)

• Dimensions: 3.5 x 13 x 14.5 cm

Interface and Circuit Protection

The 1771-OW module is built to withstand the rigors of power plant and factory floor environments. It provides robust galvanic isolation between the output contacts and the backplane logic, safeguarding the PLC-5 processor from electrical transients and field-side surges.

For simplified maintenance and installation, the module utilizes a swing-arm wiring assembly (1771-WD), allowing for module replacement without disconnecting individual field wires. Status indicators on the front panel provide real-time visual diagnostics for each output channel, streamlining troubleshooting. This module is widely used in applications involving motor starters, solenoids, and pilot lights where reliable mechanical switching is preferred over solid-state alternatives.