PLC-5 – The 1980s workhorse

Historically, it was one of the first platforms that could be programmed by a personal computer, with initially the software (A.I) written by Icon, a third party developer, independent of Allen-Bradley. A-B then brought out their own, inferior programming product, 6200, but provided a whole-of-site licence with the purchase, aiming to put A.I out of business. Eventually, Rockwell Automation bought A-B, and Icon as well.

PLC-5 Conversion to ControlLogix

Discontinued from June 2017, supplies will eventually run out, though there are still spares available on eBay, As the price has increased, and they reach 20 or even 30 years in service, migration to ControlLogix is the standard approach to avoiding failure risk.

Pyramid Integrator

The Pyramid Integrator (PLC-5/250) was the most sophisticated model in the family, allowing multiple (up to 4) CPUs in a PI chassis. The PLC-5/250 processor stores and executes compiled instruction code, which executes faster than interpreted code.  Input data can come from other Pyramid Integrator modules in the local chassis and from devices connected to the RM or KA via a DH or DH+ link.

You can have up to four LP modules in one Pyramid Integrator chassis. Each LP executes its own ladder-logic program. The LP has memory for storing ladder-logic programs and data tables. The PLC-5/250 processor stores and executes compiled instruction code, which executes faster than interpreted code.

PI Software

The Pyramid Integrator used model 6200 software, for which there were two versions; an online only package, and an online/offline package. (6201-PLC5 vs 6203-PLC5). There were versions for both DOS and VMS. The VMS version had only one version online/offline.

PLC 5 CPU / Controller Versions with Required Battery