Allen‑Bradley 1771‑OJA Isolated AC Output Module

The Allen‑Bradley 1771‑OJA is an isolated AC digital output module for PLC‑5 1771 I/O rack system. It provides 8 isolated AC output channels, driving field AC‑powered actuators such as contactors, solenoid valves and indicator lamps, with channel‑by‑channel isolation for enhanced anti‑interference performance.

This rack‑slot I/O module communicates with PLC‑5 CPU via 1771 back‑plane bus, supports standard wiring arm accessories for field connection. It acts as critical aftermarket spare for maintenance, overhaul and retrofitting of legacy PLC‑5 automation control systems in manufacturing and process‑industry sites.

Main Specifications

• Brand: Allen‑Bradley (Rockwell Automation); Model:1771‑OJA; Type: Isolated AC Digital Output Module
• Applicable System: Allen‑Bradley PLC‑5 series 1771 I/O rack automation system
• Channels: 8 isolated AC output channels; Rated operating voltage: 120V AC
• Interface: 1771 back‑plane bus; Matching wiring arm for field‑signal wiring connection
• Function: PLC logic signal conversion to AC field output, channel‑level electrical isolation, status indication
• Feature: Channel‑to‑channel isolation, LED channel status indicator, rack slot‑mount structure
• Installation: Slot‑mount inside standard 1771 series PLC‑5 I/O rack
• Operating Environment:0℃ ~ +60℃, 5%‑95% RH non‑condensing
• Certifications: CE compliant for industrial PLC automation applications

Core Functions

• Receive digital logic commands from PLC‑5 CPU through rack back‑plane bus and convert into AC switching output signals.
• Independently drive field AC‑type loads including solenoid valves, contactors and local indicator lights via 8 isolated channels.
• Realize channel‑by‑channel electrical isolation, restraining interference cross‑talk between different field‑loop circuits.
• Front‑panel LED indicators reflect on‑off status of each output channel for convenient on‑site troubleshooting.
• Work cooperatively with matching wiring arm to complete safe and reliable field‑signal wiring work.
• Complete data interaction with PLC‑5 controller to realize real‑time output response according to user‑program logic.

Application Scenarios

• Field AC‑load driving unit for legacy Allen‑Bradley PLC‑5 automation rack control systems.
• Discrete‑signal output hardware for manufacturing assembly lines, material‑handling equipment and small‑scale process‑control sites.
• Retrofit and spare replacement for legacy 1771‑series isolated AC output‑module hardware systems.
• PLC‑5 control cabinet overhaul, discrete‑loop debugging and faulty output‑module replacement projects.
• Spare‑parts inventory for industrial automation integrators and electrical engineering contractors.

• Global aftermarket spare supply for technical teams maintaining Allen‑Bradley PLC‑5 legacy automation hardware.