Product Overview

The Allen-Bradley 1785-LT/B serves as a fundamental processing unit for the PLC-5 control platform, offering a reliable solution for mid-sized industrial automation and sequential control tasks. As a Series B module, it provides a specialized architecture for managing localized and distributed I/O across industrial networks. The processor is designed to execute complex logic, timing, and counting instructions, facilitating seamless communication between human-machine interfaces (HMIs) and field devices.

This module is specifically engineered for legacy system maintenance and specialized control applications, ensuring continued operation of existing PLC-5 infrastructures. It integrates a dedicated scanner port for hardware interfacing and a Data Highway Plus (DH+) port for high-level networking and peer-to-peer data exchange.

Technical Specifications

• Processor Series: PLC-5/10 (Legacy Architecture)

• Memory Capacity: 6K words (Standard RAM); Expandable up to 14K words

• I/O Capacity: Supports up to 512 total I/O points

• Chassis Support: Up to 4 racks (1 local, 3 remote)

• Communication Ports: 1 DH+ port; 1 Remote I/O (Scanner/Adapter) port

• Memory Expansion Options: Compatible with 1785-MR (RAM) and 1785-MJ (EEPROM)

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

• Physical Weight: 1.44 kg (approx. 3.17 lbs)

• Dimensions: 4.6 x 16 x 27.4 cm

• Mounting: Left-most slot of 1771 I/O Chassis

Key Technical Characteristics

• Network Integration: The onboard Data Highway Plus (DH+) interface allows for robust communication with SCADA systems, programming terminals, and other PLC-5 or SLC 500 controllers.

• I/O Versatility: Capable of addressing 16-point or 32-point modules, the 1785-LT/B efficiently manages a mix of digital and analog signals across remote racks.

• Rugged Reliability: Built to withstand harsh industrial environments, the module features high shock and vibration resistance, meeting global EMC standards for electromagnetic compatibility.

• Expandable Architecture: Users can enhance system reliability by utilizing EEPROM backup modules, preventing data loss during extended power outages or battery failures.

• Diagnostic Capabilities: Integrated LED indicators on the front panel provide real-time status updates on processor health, battery levels, and communication activity to simplify troubleshooting.