1769-ECR Allen-Bradley Compact I/O Right Bus Terminator

Product Overview

The Allen-Bradley 1769-ECR is a critical component for any CompactLogix™ system, serving as the Right End Cap and bus terminator. This module is required to terminate the communication bus of a 1769 I/O bank, ensuring signal integrity and proper backplane operation. Without the 1769-ECR, the controller will not be able to communicate with the I/O modules in the bank, making it an essential piece for system startup and stability.

Technical Configuration

• Manufacturer: Rockwell Automation / Allen-Bradley
• Product Line: CompactLogix / 1769 Compact I/O
• Catalog Number: 1769-ECR
• Module Type: Right End Cap / Terminator
• Current Draw: 5 mA at 5V DC
• Backplane Current: 1.4 Amps at 24V DC
• Enclosure Type: Open-style Rating

Technical Specifications

Installation & System Roles

1. Essential Termination: Every CompactLogix 1769 I/O bank must be terminated with an end cap. The 1769-ECR is installed on the far right side of the last I/O module in the bank. It physically completes the internal communication bus, allowing the processor to recognize the end of the rack.

2. Power Considerations: While the 1769-ECR has a minimal bus current draw of 5 mA at 5V DC, it is rated for a total power consumption of 33.6W. Ensure your 1769 power supply has adequate headroom to support the entire bank including this termination module.

3. Handling & Safety: This module does not support Removal and Insertion Under Power (RIUP). Attempting to remove or install the end cap while the system is powered may result in a major controller fault or damage to the I/O backplane connectors.

Engineering Advantages

The 1769-ECR provides a mechanical and electrical finish to the 1769 platform. Its robust vibration resistance (5 g) ensures it maintains bus contact even in high-vibration machinery environments. By meeting T4 IEC temperature codes, it is suitable for a wide range of global industrial applications, ensuring the communication signals within the CompactLogix backplane remain noise-free and properly balanced.

Technical FAQs

Q1: Can I use a left end cap instead of a 1769-ECR?
A1: No, the 1769-ECR is specifically designed for the right side of the bank. Left-side termination is typically handled by the controller or a power supply module depending on the rack configuration.

Q2: Why is my controller showing an I/O fault after assembly?
A2: A common cause is a missing or improperly seated 1769-ECR. Ensure the end cap is firmly snapped into the last module to complete the bus circuit.

Q3: Does this module require any software configuration?
A3: No, the 1769-ECR is a passive electrical terminator and does not require a software identity or configuration in Studio 5000.