Allen Bradley 1771-ASB Remote I/O Adapter Module

Feature & Principle

It is Rockwell Allen‑Bradley classic remote I/O adapter module for PLC‑5 control system. It works as the gateway between the PLC‑5 RIO scanner port and local 1771 I/O backplane. It converts serial RIO bus signal and parallel backplane I/O data bidirectionally. Multiple ASB racks can be daisy‑chained on one twinaxial cable link. It supports 1/2‑slot, 1‑slot, 2‑slot addressing mode, configured by DIP switches for rack number and baud rate. Commonly used for old production line retrofitting and maintenance.

Specifications

Model: 1771-ASB Brand: Allen Bradley (Rockwell) Compatible CPU: PLC‑5 series Communication medium: Twinaxial cable Belden 9463 Baud rate: 57.6 kbps / 115.2 kbps / 230.4 kbps Max distance: 3048m at 57.6kbps Backplane: 1771 chassis, install at the leftmost slot Backplane current: 1A @ 5VDC Power consumption: 5.2W Application: Packaging, metallurgy, water treatment old PLC‑5 distributed control system Certification: CE, UL

Components & Diagnostics

RIO transceiver circuit, backplane interface chip, DIP switch bank, status LED indicators, wiring terminal. Common faults: RIO link interruption, baud rate mismatch, backplane contact failure, module overheating, communication timeout alarm.

Product Brief

1771-ASB remote I/O adapter module, Allen Bradley PLC‑5 classic distributed I/O communication spare widely used for old automation line overhaul and replacement.