Question 1

When did Rockwell discontinue the PLC-5?

Accepted Answer

Rockwell Automation discontinued Allen-Bradley PLC-5 hardware in June 2017. Spare parts continued to be available through authorised distributors afterwards, but are increasingly scarce. Support for the PLC-5 programming environment (RSLogix 5) has been limited for years.

Question 2

How complex is migrating PLC-5 ladder to Studio 5000?

Accepted Answer

Rockwell provides conversion tools (Migration Assistant in Studio 5000) that automatically convert part of the PLC-5 ladder logic. However: DH+ and Remote I/O communication blocks, MSG instructions and custom routines require manual adaptation. We inventory the code before providing a project estimate.

Question 3

Does the HMI also need replacing?

Accepted Answer

In most cases yes. PLC-5 installations often use PanelView Standard or older PanelView Plus versions that are no longer compatible with ControlLogix via DH+. Modern replacement is PanelView Plus 7 or FactoryTalk View ME. We include HMI migration in the project estimate.

Question 4

What are the communication challenges in a PLC-5 migration?

Accepted Answer

PLC-5 uses DH+ (Data Highway Plus) and Remote I/O as primary communication. ControlLogix uses EtherNet/IP. The transition requires new cabling and often replacement of I/O racks or use of ControlNet bridges as an interim solution. This is typically a significant cost item.

Allen-Bradley PLC-5 migration to ControlLogix

Allen-Bradley PLC-5 models

PLC-5 → ControlLogix: key steps

Code conversion

Hardware replacement

Communication upgrade

FAT + SAT

Frequently asked questions about PLC-5 migration

Planning a PLC-5 to ControlLogix migration?