Overview
The Allen-Bradley 1771-IAD is a discrete digital input module designed for the 1771 family of Programmable Logic Controllers. This module provides 16 isolated input channels for 120VAC / 125VDC input voltage, with operating voltage range of 79–138V AC or DC. The 1771-IAD is used to interface discrete devices such as pushbuttons, switches, auxiliary contacts from relays, contactors and other devices. This input module installs directly into compatible 1771 I/O chassis and communicates through the PLC-5 backplane.
Key Features
- Sixteen (16) input channels compatible for 120VAC / 125VDC input voltage
- Adjustable input filtering to minimize false triggering in electrically noisy environments
- Compatible with 1771-A1B, A2B, A3B, A3B1, A4B chassis and 1771-AM1, AM2 universal I/O chassis
- Signal delay (typical) on AC = 5 (±3) ms
- Backplane current: 195 mA @ 5V DC
- Isolated input channels for galvanic separation from control logic
Technical Specifications
The module features rugged industrial-grade construction suitable for plant-floor environments. The 1771-IAD weighs 0.99 lbs and supports 50/60 Hz operation. This is a discontinued product as of March 10, 2020, but remains in active service across legacy PLC-5 systems.
Typical Applications
- Machine control and automation systems using PLC-5 platforms
- Discrete device monitoring in manufacturing and process control
- Pushbutton and switch interface circuits
- Relay and contactor status feedback
- Safety and emergency stop circuit integration
- Building automation and plant floor I/O expansion
Compatibility & Replacements
Compatible With
- PLC-5 controller systems
- 1771-A1B, A2B, A3B, A3B1, A4B chassis
- 1771-AM1 and AM2 universal I/O chassis
- 1771 discrete I/O backplane networks
- ControlNet, Remote I/O, and Extended Local I/O networks
Replaces / Drop-In Replacement For
- Existing 1771-IAD/A, 1771-IAD/B, 1771-IAD/C, and 1771-IAD/D revisions
- Equivalent Allen-Bradley legacy discrete input modules
Works With
- Allen-Bradley RSLogix 5 programming software
- PLC-5 instruction sets and ladder logic
- 1771-Series I/O chassis communication protocols
- Discrete AC/DC field device networks
