The Allen Bradley 1771-IT is a PLC-5 series fast-response DC digital input module designed for the 1771 I/O platform. It is engineered for high-speed signal detection in industrial automation environments where rapid response to field device status changes is critical.
This module is commonly used in motion-related systems, high-speed machine control, and applications requiring faster input transition detection than standard DC input modules.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | Allen Bradley (Rockwell Automation) |
| Catalog Number | 1771-IT |
| Module Type | Fast DC Input Module |
| System Family | PLC-5 / 1771 I/O |
| Input Channels | 8 inputs |
| Input Voltage Range | 12–72V DC |
| Nominal Voltage | 24V / 48V / 60V DC applications |
| Input Type | Sink input (source load compatible) |
| Backplane Current Draw | ~74 mA @ 5 V DC |
| Input Current | ~8 mA @ 12V DC / 24 mA @ 24V DC |
| On-State Delay | ~0.6 ms (±0.2 ms typical) |
| Off-State Delay | ~50 ms maximum |
| Off-State Current | ≤ 1.3 mA |
| Isolation | Opto-electrical isolation |
| Wiring Arm | 1771-WH / 1771-WA |
| Mounting Type | 1771 chassis slot |
| Operating Temperature | 0°C to 60°C |
| Storage Temperature | -40°C to 85°C |
| Weight | ~0.40 kg |
| Dimensions (L×W×H) | 203 mm × 76 mm × 127 mm |
System Role Overview
The 1771-IT module is designed for high-speed DC signal acquisition within PLC-5 control systems. It enables rapid detection of field input changes for time-sensitive industrial applications.
Core functions include:
- Fast-response digital input monitoring
- High-speed machine signal detection
- Integration with PLC-5 high-performance control systems
- Reliable operation in electrically noisy environments
- Support for industrial DC switching devices
Its fast ON-state response makes it suitable for applications requiring rapid event capture.
Recommended Related Modules
| Model | Function |
|---|---|
| 1771-IBD | Standard DC input module |
| 1771-IBN | High-density DC input module |
| 1771-OBD | DC output module |
| 1771-OWNA | Relay output module |
| 1771-IFE | Analog input module |
| 1771-ASB | Remote I/O adapter |
Popular Allen Bradley PLC-5 Modules
| Model | Function |
|---|---|
| 1785-L40B | PLC-5 processor |
| 1771-A4B | 16-slot I/O chassis |
| 1771-DMC | Data Highway communication module |
| 1771-SN | I/O scanner module |
| 1771-ALX | Local I/O adapter module |
