Product Overview
The Allen-Bradley 1771-IA2 is a digital input module from the PLC 5 family, manufactured by Rockwell Automation. It converts AC or DC signals from user devices into logic levels for the processor, directly controlling bits in the PLC data table. This module is intended for use with AC/DC proximity switches, pushbuttons, limit switches, and other on/off sensors. Its modular design and 1771-WA wiring arm simplify installation and replacement without rewiring.
Technical Specifications Breakdown
Key parameters for the 1771-IA2 are listed below for quick reference:
| Feature | Specification |
|---|---|
| Module Type | Digital Input Module |
| Voltage Rating | 120 Volts AC/DC |
| DC Operating Voltage | 97-138 Volts |
| Backplane Current | 75 Miliamperes |
| Max AC Off-State Current | 2.8 Miliamperes |
| Max DC Off-State Current | 2.8 Miliamperes |
| Typical AC Signal Delay (On) | 24 (+/- 10) ms |
| Typical DC Signal Delay (On) | 10 (+/- 4) ms |
| Typical AC Signal Delay (Off) | 24 (+/- 10) ms |
| Typical DC Signal Delay (Off) | 20 (+/- 9) ms |
| Dimensions | 3.5 x 6.5 x 2.0 in (89 x 165 x 51 mm) |
Industry Applications
This module is well-suited for discrete manufacturing lines where 120V AC/DC sensors and actuators are common. For example, in automotive assembly, it can interface with proximity switches to detect part presence. In packaging, it monitors limit switches on conveyor systems. The 1771-IA2 provides reliable signal conversion, reducing downtime from false triggers.
Installation & Setup Guidance
Mount the module in a 1771 I/O chassis with a PLC processor. Use the 1771-WA wiring arm to connect field wiring without disconnecting individual wires. Keying bands between pins 10 and 12 (upper connector) and pins 4 and 6 (lower connector) ensure correct slot placement. The module supports ½, 1, and 2-slot I/O addressing. Verify DC operating voltage is within 97-138 Volts before powering.
Maintenance & Reliability
Inspect the module periodically for loose connections or environmental contaminants. The front panel has 8 orange status indicators for field-side diagnostics. Input filtering reduces electrical noise, and optoelectrical isolation protects system circuits from transients. No special maintenance beyond routine checks is required.
Compatibility & Integration
The 1771-IA2 integrates with any PLC 5 system using a 1771 I/O chassis. It works with AC/DC proximity switches and other on/off devices. The 1771-WA wiring arm is included for easy replacement.
Selection Guide & Purchasing Advice
When selecting a digital input module for 120V AC/DC applications, the 1771-IA2 offers proven reliability. Please verify current lifecycle status and availability with AutoDCSTech before ordering.
Troubleshooting & Common Issues
If inputs fail to register, check the DC operating voltage (97-138 Volts) and off-state current (max 2.8 mA). Verify keying bands are correctly positioned. Signal delays are normal; AC delays average 24 ms, DC delays vary (10 ms on, 20 ms off). For persistent issues, inspect the 1771-WA wiring arm for damage.
Availability & Condition at AutoDCSTech
| Part Number | 1771-IA2 |
|---|---|
| Availability | In Stock |
| Condition | New |
| Warranty | One Year |
| Origin | US |
