1771-ASB/E Allen-Bradley Universal Remote I/O RIO Chassis Adapter

Product Description

The Allen-Bradley 1771-ASB/E is a Universal Remote I/O (RIO) adapter module. This hardware establishes communication between a central PLC-5 processor chassis and a remote 1771 I/O chassis. By decentralizing the control architecture, the unit allows users to place I/O modules closer to field sensors and actuators. Consequently, this architecture significantly reduces long-run wiring expenses and accelerates deployment times.

Key Technical Specifications

• Product Range: PLC-5 / 1771 Platform
• Module Type: Remote I/O (RIO) Adapter Module
• Series: Series E
• Backplane Current Load: 1.0 Ampere at 5 Volts DC
• Communication Media: Allen-Bradley twinaxial cable (Blue Hose, Catalog No. 1770-CD)
• Supported Baud Rates: 57.6 Kbps, 115.2 Kbps, and 230.4 Kbps
• Maximum Cable Distance: 10,000 feet (3,048 meters) at 57.6 Kbps
• Status Indicators: Active, Adapter Fault, and I/O Rack Fault LEDs
• Approximate Weight: 0.9 kg (2.0 lbs)
• Dimensions: 3.5 cm x 13.0 cm x 14.5 cm
• HS Code: 8537101190

Functional Capabilities and Features

The module scans the local 1771 chassis backplane. It continuously updates the I/O data table images. Afterward, it transmits this data to the host controller over the RIO network link. The device supports 1/2-slot, 1-slot, and 2-slot I/O addressing configurations. This flexibility allows for dense discrete and analog module arrangements.

Furthermore, the hardware provides high-speed backplane scanning to maintain optimal system response times. Operators can quickly diagnose network performance using the three front-panel LED indicators. These diagnostics separate internal module faults from external network cabling errors.

Industrial Application and Network Topology

Industrial facilities utilize this adapter to extend control loops across large physical plants. Typical applications include water treatment facilities, material handling systems, and automotive assembly lines. The adapter terminates the remote drop on the RIO link using standard terminating resistors. Because it operates independently of standard Ethernet networks, it requires no Ethernet routing configuration. Instead, it relies on physical DIP switches for rack address and baud rate selection.