Industrial Automation Is Seeing Modular Application Software GrowIndustrial Automation Is Seeing Modular Application Software Grow

Transitions in automation control programming over the years from relay ladder logic, to PLC ladder logic, to even today's use of IEC 61131-3 PLC languages have maintained a fundamental connection with ladder logic programming and the use of graphical circuit diagrams from its relay logic roots.

Even with modern programming methods taking center stage, ladder diagram (LD) still has its place as one of the six IEC 61131-3 programming languages. LD has a significant user base, especially among plant service and support personnel who understand how ladder technology works and how to use its tools to troubleshoot sophisticated systems on the plant floor.