Allen-Bradley 1771-IH Digital DC Input Module for PLC-5 Systems

Product Overview

When your PLC-5 system requires reliable digital DC input sensing, the Allen-Bradley 1771-IH delivers consistent performance. This input module is part of the Bulletin 1771 family and provides 8 input channels for monitoring DC signals in industrial environments. Designed for rack mounting, the 1771-IH simplifies installation with its wiring arm, making it a practical choice for control panels and machinery.

The 1771-IH operates with a DC voltage category of 10-60 Volts DC, sink (source load), and a DC operating voltage range of 24-50 Volts. This flexibility allows it to interface with various sensors and switches commonly found in manufacturing lines. With an earlier model status, it remains a viable option for legacy system maintenance and expansion.

Technical Specifications

The 1771-IH is a digital DC input module with 8 inputs. Its voltage category spans 10-60 Volts DC, sink (source load), and the DC operating voltage is 24-50 Volts. The backplane current draw is 74 milliamperes. Maximum DC off-state current is 0.7 milliamperes. Typical DC signal delay on is 15 ms (+/- 7 ms), and off is 20 ms (+/- 9 ms). Typical AC signal delay off is 24 ms (+/- 10 ms). The module uses a 1771-WA wiring arm and is rack mountable.

Industry Applications

In automotive assembly lines, the 1771-IH monitors limit switches and proximity sensors to verify part presence and position. Its 24-50V DC operating range matches standard industrial sensor outputs, reducing the need for additional signal conditioning. For material handling systems, the module tracks conveyor status and safety interlocks, ensuring smooth material flow. The 8-input density suits moderate I/O requirements without wasting rack space.

Installation & Setup Guidance

Mount the 1771-IH in any available slot of a 1771 I/O chassis. Use the provided wiring arm (1771-WA) to connect field wiring securely. Ensure the DC supply voltage is within the 24-50 Volt range and observe polarity. The module is keyed to prevent incorrect insertion. After installation, verify input status using the red LED indicators on the front panel.

Compatibility & Integration

The 1771-IH is designed for Allen-Bradley PLC-5 processors and 1771 I/O platforms. It integrates directly with the backplane, communicating input states to the processor without additional adapters. For system upgrades, it can coexist with other 1771 analog and digital modules in the same rack.

Selection Guide & Purchasing Advice

Before purchasing the 1771-IH, confirm your system voltage requirements match the 24-50V DC operating range. Verify that your chassis has an available slot and that the wiring arm is included or ordered separately. BluePLC Industrial stocks the 1771-IH and can advise on availability and compatibility with your existing PLC-5 installation. For complete technical specifications, contact BluePLC Industrial.