When a PLC is used primarily to replace relays, timers, and counters, it's hard to beat the simplicity and usefulness of ladder diagram programming. Their ability to accept programming in ladder ...

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 ...

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 ...