The first Programmable Logic Controllers were designed and developed by Modicon as a relay re-placer for GM and Landis.
These controllers eliminated the need for rewiring and adding additional hardware for each new configuration of logic.

The new system drastically increased the functionality of the controls while reducing the cabinet space that housed the logic.


The first PLC, model 084, was invented by Dick Morley in 1969.

The first commercial successful PLC, the 184, was introduced in 1973 which was designed by Michael Greenberg.