Allen-Bradley 1771-ID16 Digital AC/DC Input Module for PLC-5

Product Introduction

As industrial automation evolved from relay panels to programmable controllers, the need for robust, noise-immune input modules became critical. The Allen-Bradley 1771-ID16 digital AC/DC input module addresses this challenge directly. Part of the PLC-5 family, this module provides 16 isolated inputs that handle both AC and DC signals, making it a versatile choice for legacy and modern control systems. Its selectable input filtering suppresses voltage transients from contact bounce and electrical noise, improving power quality and extending equipment life. Whether you are upgrading an existing PLC-5 rack or maintaining a critical production line, the 1771-ID16 delivers reliable signal conditioning for float switches, limit switches, pushbuttons, and selector switches.

Technical Specifications

The 1771-ID16 operates with an AC voltage range of 77 to 138 Volts and a DC voltage range of 105 to 138 Volts. It draws 75 milliamperes from the backplane. The maximum off-state current is 4.0 milliamperes for AC and 1.8 milliamperes for DC. Signal delay times vary: typical AC turn-on delay is 1 ms, AC turn-off delay is 9 or 18 ms; DC turn-on delay is 1 ms, DC turn-off delay is 9 ms. The module measures 3.5 x 6.5 x 2.0 inches (89 x 165 x 51 mm) and ships with the 1771-WN wiring arm for easy connection.

Industry Applications

In discrete manufacturing, the 1771-ID16 monitors limit switches on conveyor systems, ensuring accurate part positioning. In process industries, it interfaces with float switches in tank level monitoring, where its selectable filtering prevents false triggers from fluid turbulence. For multi-phase isolated-circuit applications, the module works seamlessly with selector switches and pushbuttons, providing clean input states to the PLC-5 processor. Its ability to handle both AC and DC signals simplifies inventory and reduces the need for multiple module types.

Installation & Setup Guidance

Mount the 1771-ID16 in a 1771-A1B, 1771-A4B, or later I/O chassis. The included 1771-WN wiring arm attaches to the chassis pivot bar, allowing module insertion or removal without disconnecting field wiring. Connect field devices to the 40-terminal wiring arm per the module's wiring diagram. Select the desired input filter time via the module's DIP switch; the factory setting is 9 ms. Verify that the AC or DC operating voltage falls within the specified ranges before powering the system.

Maintenance & Reliability

Periodically inspect the 1771-WN wiring arm for loose connections or corrosion. Ensure the chassis cooling fans are functional to maintain ambient temperature within the PLC-5 enclosure's rated range. The module's capacitive impedance input design inherently limits inrush current, reducing stress on connected contacts. No internal cleaning or disassembly is required; routine visual checks and voltage verification at the input terminals are sufficient to maintain reliable operation.

Compatibility & Integration

The 1771-ID16 is designed for Allen-Bradley PLC-5 processors and compatible 1771 I/O chassis. It works with the 1771-A1B, 1771-A4B, and later versions. The module accepts inputs from dry contacts, proximity sensors, and other NEMA-rated devices. For system integration, refer to the PLC-5 programming manual for input mapping and filter configuration. The 1771-ID16 is not intended for use with ControlLogix or CompactLogix platforms without an adapter.

Selection Guide & Purchasing Advice

Before ordering the 1771-ID16, confirm your chassis type and available slot count. Verify that your system's AC or DC supply voltage matches the module's operating range. If you need a replacement for an existing 1771-ID16, the unit is a direct drop-in. BluePLC Industrial stocks this module and can advise on current lifecycle status and availability. Contact our team for bulk pricing or expedited shipping options.

For complete technical specifications for the 1771-ID16, please contact BluePLC Industrial.