Allen-Bradley 1769-CRR3 CompactLogix Right-to-Right Bus Expansion Cable

System Expansion Utility

The 1769-CRR3 is a specialized communication bus expansion cable designed for the Allen-Bradley CompactLogix and MicroLogix 1500 systems. This 1-meter cable enables the connection of two separate 1769 I/O banks, specifically facilitating a "Right-to-Right" configuration. It is an essential component when a control system's I/O requirements exceed the physical capacity of a single rail or when enclosure dimensions necessitate splitting the module assembly into multiple rows. By extending the 1769 backplane, the 1769-CRR3 ensures high-speed data integrity and seamless communication between the controller and remote expansion modules.

Technical Specifications

• Manufacturer: Allen-Bradley / Rockwell Automation

• Product Series: Compact I/O / CompactLogix

• Model Number: 1769-CRR3

• Function: Backplane Bus Expansion

• Connection Orientation: Right Bank to Right Bank

• Cable Length: 1 Meter (3.28 Feet)

• Operating Temperature Range: 0°C to 60°C (32°F to 140°F)

• Storage Temperature Range: -40°C to 85°C (-40°F to 185°F)

• Maximum Humidity: 95% non-condensing

• Vibration Rating: 5g @ 10...500 Hz

• Backplane Current Draw: Passive (negligible)

• Weight: 0.09 kg (0.19 lbs)

Installation and Hardware Requirements

The 1769-CRR3 requires the use of expansion end caps to properly terminate and bridge the communication bus. Because the cable utilizes a Right-to-Right orientation, it is typically used in multi-tier chassis configurations where the physical layout requires the cable to exit the right side of the top row and enter the right side of the row below. It is critical to ensure that the total distance rating of the power supply is not exceeded when adding expansion cables, as the cable itself introduces a small amount of voltage drop across the extended backplane.

Frequently Asked Questions

What is the difference between the 1769-CRR3 and the 1769-CBL1?The 1769-CRR3 is a 1-meter cable specifically for Right-to-Right bank connections, whereas the 1769-CBL1 is a shorter (approximately 0.3-meter) cable typically used for Right-to-Left connections. Choosing the correct model depends entirely on your chassis mounting orientation.

Does this cable provide power to the second bank of I/O?While the cable extends the communication bus, it does not carry sufficient current to power a second bank of high-density I/O. A separate 1769 expansion power supply (such as the 1769-PA2 or 1769-PB2) is generally required on the additional bank to ensure proper module operation.