When a PLC is used primarily to replace relays, timers, and counters, it's hard to beat the simplicity and usefulness of ladder diagram ... control either external PLC outputs or internal relay coils ...

In years past, ladder logic was made possible with discrete relays and was sometimes termed “relay logic.” Today most implementations are done using ... control circuit that will only allow the motor ...

And, if you use this standard when working with certain Arduinos, this common platform can become a standard-compliant PLC as well. The IDE itself supports programming ladder diagrams, functional ...