Overview
The Allen-Bradley 1771-ASB Series D is a universal remote I/O adapter designed for PLC-5 systems. This module provides the interface between remote I/O modules and PLC-5 controllers, enabling distributed I/O configurations in industrial automation systems. The Series D design offers flexible I/O addressing, configurable transmission speeds, and long-distance cable support, making it ideal for facilities requiring expanded control scope beyond centralized PLC proximity.
Key Features
- Multi-speed communication: Supports 57.6 kbps, 115 kbps, and 230 kbps data transmission rates for flexible installation requirements
- Extended cable distance: Transmits data up to 10,000 cable-feet at 57.6K baud; up to 2,500 feet at 230.4K baud
- Flexible I/O addressing: Supports 1/2-slot, 1-slot, and 2-slot I/O addressing methods, handling 4, 6, 8, 16, or 32-point I/O combinations
- Efficient scanning: Scans all slots in the chassis or all but the last four slots for optimized scan time and I/O image space savings
- Series B compatibility mode: Can emulate Series B adapters for compatibility with legacy 1771-S4A and 1771-S4B scanners
- Parallel/serial conversion: Receives and sends data to I/O scanner in serial form while reading/writing input and output modules in parallel form
Technical Specifications
- Backplane current load: 1.0 A at 5 V DC
- Maximum power dissipation: 5.2 W
- Weight: 1.9 pounds
- Data transmission speed: 57.6 kbps, 115 kbps, 230 kbps
- Maximum cable distance: 10,000 feet (57.6K baud); 2,500 feet (230.4K baud)
- I/O addressing modes: 1/2-slot, 1-slot, 2-slot
- I/O point support: 4, 6, 8, 16, or 32 points (any mix)
- Dimensions: 3.5 x 6.5 x 2.0 inches (89 x 165 x 51 mm)
- Certifications: UL Listed, CSA Certified, Class I Division 2 Groups A/B/C/D, CE Compliant, C-tick Marked
Typical Applications
- Distributed I/O configurations for multi-location production lines
- Remote machine monitoring and control in large manufacturing facilities
- Legacy PLC-5 system expansion and modernization projects
- Industrial facilities requiring extended control distance without additional controllers
- Retrofit installations integrating remote I/O modules with existing PLC-5 infrastructure
Compatibility & Replacements
Compatible With
- PLC-5 programmable logic controllers
- Remote I/O (RIO) modules and chassis
- Universal I/O chassis with configurable backplane
- 1771 series I/O modules of any density
- ControlNet, Ethernet, and Data Highway Plus (DH+) communication networks
Replaces / Drop-In Replacement For
- Earlier 1771-ASB Series A and Series B adapters (with Series B emulation mode)
- Systems requiring legacy remote I/O adapter functionality
Works With
- PLC-5 programming software and RSLogix 5
- Remote I/O (RIO) protocol and communication networks
- 1771 series I/O modules (input, output, and combination modules)
- Universal I/O chassis and slot-based configurations
- Wiring Arm 1771-WB for installation and terminal connectivity














