Allen-Bradley 1771-IG TTL Digital DC Input Module

Description

The Allen-Bradley 1771-IG is a TTL Digital DC Input Module designed for the PLC-5 and 1771 I/O platform. This module effectively converts DC signals from various user-supplied automation devices to the logic levels required by the processor, managing the corresponding bit states within the PLC data table. It is engineered specifically for transistor-transistor logic (TTL) and binary-coded decimal (BCD) interface encoder applications, making it well-suited for high-precision industrial data acquisition and positioning setups.

Constructed for reliable operation within standard 1771 I/O chassis, the 1771-IG integrates features to safeguard logic integrity against electrical noise. It includes provisions for a 1771-WC wiring arm, enabling simplified module replacement and maintenance without requiring the disconnection of field wiring.

Features

• Compatible with Allen-Bradley PLC-5 systems and standard 1771 I/O chassis architecture
• Designed for 5VDC TTL and BCD interface encoder applications
• Includes wiring arm compatibility (1771-WC) for fast module replacement without rewiring
• Optical isolation between field input signals and the system backplane
• Conformal-coated circuit boards for enhanced durability in harsh industrial environments

Applications

• TTL encoder interfacing and position feedback monitoring
• BCD switch data reading
• High-speed digital DC signal conversion in PLC-5 architectures
• Legacy discrete automation and process control systems

Technical Specifications

Connections / Interfaces

The 1771-IG module connects to field devices via a removable 1771-WC wiring arm attached to the front of the I/O chassis. This interface secures all sensor signal wiring, allowing the electronic module to be inserted or removed from the backplane without disturbing field terminations. Backplane communication and power are established directly through the module's rear edge connector when seated in the 1771 chassis.

Installation Guidelines

1. Ensure all power to the 1771 I/O chassis and associated rack power supply is turned off before installing or removing the module.
2. Verify that the chassis backplane power requirements are not exceeded by adding this module.
3. Mount the 1771-WC wiring arm to the swing-bar on the front of the chassis slot.
4. Align the 1771-IG module with the chassis guides and slide it smoothly into the designated slot until firmly seated against the backplane connector.
5. Secure the module using top and bottom retaining latches and swing the wiring arm into place.

Compliance and Certifications

• UL Listed Industrial Control Equipment
• CSA Certified
• CE compliant for applicable directives