The Allen Bradley 1771-IBD is a PLC-5 series DC digital input module designed for the 1771 I/O platform. It is used to interface 24V DC field devices with PLC-5 controllers, converting external DC signals into logic-level data for industrial control applications.
This module is commonly deployed in machine automation and process control systems where reliable DC signal acquisition is required across multiple input points.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | Allen Bradley (Rockwell Automation) |
| Catalog Number | 1771-IBD |
| Module Type | DC Digital Input Module |
| System Family | PLC-5 / 1771 I/O |
| Input Voltage Range | 10–30V DC (24V nominal) |
| Input Channels | 16 points |
| Input Type | Sink/Source compatible (depending on wiring) |
| On-State Voltage | ≥ 10V DC |
| Off-State Voltage | ≤ 5V DC |
| Backplane Current Draw | ~0.25 A @ 5 V DC |
| Input Filtering | Industrial noise filtering |
| Isolation | Optical isolation per group |
| Response Time | Standard PLC input filtering |
| Mounting Type | 1771 chassis slot |
| Operating Temperature | 0°C to 60°C |
| Storage Temperature | -40°C to 85°C |
| Weight | ~0.40–0.55 kg |
| Dimensions (L×W×H) | 118 mm × 35 mm × 87 mm |
System Role Overview
The 1771-IBD module is responsible for reading DC discrete signals from field devices and transmitting them to the PLC-5 processor via the backplane.
Core functions include:
- Acquisition of 24V DC digital signals
- Interface between sensors and PLC system
- Electrical isolation of field wiring
- Stable signal filtering in industrial environments
- Integration into PLC-5 distributed I/O systems
It is widely used in modernized legacy PLC-5 installations and long-life industrial systems.
Recommended Related Modules
| Model | Function |
|---|---|
| 1771-IAD | AC digital input module |
| 1771-OBD | DC digital output module |
| 1771-OWNA | Relay output module |
| 1771-IFE | Analog input module |
| 1771-P7 | Chassis power supply |
| 1771-ASB | Remote I/O adapter |
Common PLC-5 System Modules
| Model | Role |
|---|---|
| 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 |
