Allen-Bradley 1785-L80E PLC5/80E Programmable Logic Controller Overview

Product Introduction

When your large-scale application demands reliable control of both discrete and analog processes, the Allen-Bradley 1785-L80E delivers proven performance. This programmable logic controller from the PLC5 family handles complex control requirements including motion, calculation, counting, and advanced algorithms like PID. With 100 KWords of user memory and embedded Ethernet, DH+, and serial communication, it integrates seamlessly into existing plant networks.

Technical Specifications Breakdown

The 1785-L80E features a memory capacity of 100 KWords for storing user programs and configuration data. It supports a maximum of 3072 total I/O points (any mix) or 3072 inputs plus 3072 outputs in complementary mode. Power dissipation is rated at 17.3W, and the backplane current load is 3.3A (per description: 3.6A). The controller uses a 1770-XYC battery to maintain volatile memory and accepts 1785-ME16, -ME32, -ME64, or -M100 memory modules for backup. It can manage up to 93 I/O racks with a maximum of 32 remote I/O chassis per link.

Industry Applications

In manufacturing plants, the 1785-L80E controls assembly lines requiring high-speed discrete logic and analog feedback loops. For example, a food processing facility uses this controller to manage conveyor speeds, temperature profiles, and packaging machinery simultaneously. In water treatment, it handles pump sequencing, flow monitoring, and chemical dosing with PID loops. The embedded Ethernet port simplifies data exchange with SCADA systems, reducing integration costs.

Installation & Setup Guidance

Install the 1785-L80E in the leftmost slot of a 1771 I/O chassis. Ensure the power supply is one of the compatible models: 1771-P4S, -P6S, -P4S1, or -P6S1. Connect the 25-pin RS-232 serial port for programming using DF1 protocol. Use the 8-pin mini-DIN port for terminal access. The two combo ports (Channels 1A and 1B) can be configured as DH+ or Remote I/O adapter/scanner. The Ethernet port supports 10/100 Mbps with auto-negotiation. Verify that the backplane current draw does not exceed the chassis rating.

Compatibility & Integration

The 1785-L80E works with 8-point, 16-point, 32-point, and 1771 intelligent I/O modules. It communicates via DH+ networks, Remote I/O links, and Ethernet. The serial port supports RS-232, RS-423, and RS-422A standards. Use the control coprocessor expansion port for additional processing power. The processor supports 2-slot, 1-slot, and half-slot I/O addressing modes for flexible module placement.

Selection Guide & Purchasing Advice

Before purchasing the 1785-L80E, verify that your application requires 100 KWords of memory and Ethernet connectivity. Confirm compatibility with your existing 1771 chassis and power supply. The 1785-L80E is a legacy product; please verify current lifecycle status and availability with BluePLC Industrial before ordering. BluePLC Industrial offers reliable sourcing for this controller and compatible accessories such as the 1770-XYC battery and 1785-ME series memory modules.