Allen-Bradley 1785-L60B PLC-5 Processor 64K Memory

June 11, 2026 • 3 min read • wayne • Science

Product Summary

The Allen-Bradley 1785-L60B is a powerful PLC-5 processor that delivers robust control for demanding applications. It manages up to 64K Words of user memory and supports 3072 total I/O points. This unit provides four DH+ and Remote I/O ports, one serial port, and two programming terminals for flexible integration.

Expert Technical Evaluation & Performance Review

The 1785-L60B operates as an enhanced Ethernet PLC-5 controller from Rockwell Automation. It uses battery-backed static RAM to retain critical programs. This memory supports expansion modules like the 1785-ME16, ME32, and ME64. The processor scans I/O racks at 10 ms at 57.6 kbits/s. This speed drops to 3 ms at 230.4 kbits/s for faster networks. The unit controls up to 93 total I/O chassis. Of these, 92 can operate as remote chassis.

The processor supports three distinct I/O addressing modes. The 2-slot mode handles 8-point modules and pairs of 16-point modules. The 1-slot mode works with 8 or 16-point modules and pairs of 32-point modules. The half-slot mode addresses any mix of 8, 16, and 32-point modules. This flexibility makes it ideal for diverse field wiring layouts.

The communication ports use specific connectors for reliable data transfer. The DH+ and RIO ports use 3-pin terminals with Belden 9463 cable. The programming ports use 8-pin mini-DIN circular connectors. The serial port uses a 25-pin sub-D connector for ASCII and DF1 protocols. Status LED indicators show battery condition, run or fault mode, force activity, and channel 0 communication status.

Product Procurement & Buyer Guide

Engineers and procurement managers must consider memory and I/O requirements. The 1785-L60B offers 64K Words of user memory. This is sufficient for medium to large control programs. The controller handles 3072 input and output signals in any mix. It can also manage 3072 inputs plus 3072 outputs in complementary mode.

The unit requires a 1770-XYC internal battery for memory backup. This battery discharges completely 30 days after the BATT LED activates. You can add backup memory modules to prevent program loss. Compatible modules include the 1785-ME16, ME32, ME64, and ME100. You must plan for this to avoid unexpected downtime.

The processor operates in harsh industrial environments. It withstands operational shock of 30G and vibration of 2G at 10 to 500 Hertz. The temperature range spans 0 to 60 °C. The unit works at 5-95% relative humidity without condensation. These specifications ensure reliable performance on the factory floor.

The unit weighs approximately 1.42 kilograms or 3 pounds. It comes in an open-style enclosure for easy panel mounting. The processor holds certifications from UL, C-TICK, CE, and CSA. These approvals simplify compliance for global automation projects.