Ladder logic uses switch or relay contacts to implement Boolean expressions. In years past, ladder logic was made possible with discrete relays and was sometimes termed “relay logic.” Today most ...

When learning ladder logic, I was told that some new PLC systems were moving to scripted programming languages. My instructor assured us that we would not need to know anything other than ladder logic ...

Logic gates are the bricks and mortar of digital electronics, implementing a logical operation on one or more binary inputs to produce a single output. These operations are what make all computations ...

A family of programming languages for programmable logic controllers (PLCs). Of the three graphical and two textual languages, ladder logic (see example below) was the first language and widely used.

In part one of this series, we looked at the PLC’s internal architecture, briefly discussed Ladder Logic programming, Human-Machine Interfaces, advantages of the PLC’s ability to react consistently ...