Allen-Bradley 1771-OD16 Overview
The Allen-Bradley 1771-OD16 is a 16-point isolated AC output module designed for PLC-5 systems within the 1771 I/O chassis family. This module provides solid-state switching of AC loads and is optimized for controlling devices such as motor starters, pilot lights, and solenoids. The isolation design protects your processor and other I/O from transient voltage spikes common in industrial environments.
Key Features
- 16 isolated digital output channels with individual control
- Solid-state (triac) switching for AC loads
- 2A per channel continuous current, 8A module total (peak surge 20A)
- Operating voltage range 74–138V AC, 47–63 Hz
- High isolation voltage: 2500V DC tested for 1 second
- Metal-oxide varistor (MOV) protection between terminal sets to suppress transient voltage spikes
- Compatible with 1771-A1B, 1771-A2B, 1771-A3B, and 1771-A4B chassis
Technical Specifications
- 16 digital outputs
- Output voltage: 74–138V AC
- Output frequency: 47–63 Hz
- Continuous current per channel: 5 mA to 2A
- Module total current: 8A continuous
- Peak current surge: 20A (100 ms pulse every 2 seconds)
- Per-output voltage drop: 5.8V RMS (at load < 50 mA); 1.5V RMS (at load > 50 mA)
- Isolation voltage: 2500V DC (1 second)
- Fuse protection: 3A 2AG slow-blo per channel (recommended)
- Backplane keying: pins 22–24 and 34–36
Typical Applications
- AC motor starter control
- Solenoid valve switching
- Pilot light and annunciator drivers
- Industrial machinery control in legacy PLC-5 systems
- Process automation requiring isolated AC switching
Compatibility & Replacements
The 1771-OD16 is designed to integrate into PLC-5 automation systems. Note: This module was discontinued by Rockwell Automation as of December 31, 2016. For new installations, Rockwell recommends engineering replacements from their current I/O portfolio. However, the 1771-OD16 remains widely available in the used/surplus market for legacy system maintenance and repair. Compatible chassis include 1771-A1B, 1771-A2B, 1771-A3B, and 1771-A4B backplanes. Installation instructions and technical documentation are available through Rockwell’s Literature Library.
