PLC-5 Processor Allen-Bradley 1785-L80B Enhanced Controller

Product Overview

The 1785-L80B is a powerful enhanced PLC-5 controller from Allen-Bradley. It has 100,000 words of user memory. This processor handles up to 3072 I/O points. It supports both inputs and outputs in any mix. The unit features four communication channels. These channels can act as DH+ or Remote I/O ports. Each channel also works as a scanner or adapter. One serial port is configurable for RS-232, RS-423, or RS-422A. Two programming terminals are built in. The controller runs on a 1771 chassis. It uses a 1770-XYC battery for memory backup.

Application Scenarios

This controller works well in large industrial systems. It connects many remote I/O racks and devices. Use it for manufacturing lines, conveyor systems, and material handling. It also fits water treatment plants and oil refineries. The four DH+ ports allow peer-to-peer communication. This makes it easy to link multiple PLC-5 controllers. The Remote I/O ports handle real-time data exchange. Operators can monitor and control equipment remotely. The RS-232 port connects to programming devices or HMI panels.

Technical Specifications

The 1785-L80B has 100 kilowords of battery-backed RAM. Maximum I/O chassis count is 93. Total I/O is 3072 analog or digital. It supports 32 remote I/O racks. I/O scan time is 10 ms at 57.6 kbps. It goes to 7 ms at 115.2 kbps and 3 ms at 230.4 kbps. The backplane current draw is 2.3 A. Power dissipation is 12 W. Communication protocols include DF1, ASCII, DH+, and Remote I/O. Memory expansion modules are available: 1785-ME16, ME32, ME64, and M100. EEPROM backup is optional with those modules. Controller redundancy is supported. The front panel has status LEDs for battery, processor mode, forces, and communication.

Installation & Maintenance Guide

Install the 1785-L80B in a 1771-A1B, A2B, A3B, A3B1, or A4B chassis. Use compatible power supplies like 1771-P4S1, P6S1, P4R, or P6R. Ensure proper backplane seating. Connect DH+ cables with correct termination. Maximum cable length is 3048 m at 57.6 kbps. It decreases to 762 m at 230.4 kbps. All devices on a DH+ link must use the same speed. For serial port, use shielded cables. Replace the battery 1770-XYC when the BATT LED is on. Keep the controller in a clean, dry environment. Check airflow around the chassis. For detailed wiring, refer to the user manual.

Packing List

The package includes one Allen-Bradley 1785-L80B processor. It comes with a user manual on CD. A battery 1770-XYC is pre-installed. No cables or adapters are included. Shipping is via FedEx, UPS, or DHL. Standard handling time is 1 to 2 business days.