Ladder logic is the basis of most control functions Ladder logic uses switch or relay contacts to implement Boolean expressions. In years past, ladder logic was made possible with discrete relays and ...

Scan rate — 18mS/1K of logic. For more background on PLC operations, you can review past Motor Facts articles that deal with magnetic motor starters, input and output devices, and ladder logic by ...

Of the three graphical and two textual languages, ladder logic (see example below) was the first language and widely used. IEC 61131 was previously known as IEC 1131.