Ladder logic (LAD) is a graphical language similar to electrical relay diagrams. When writing programs in LAD, you use graphical components and arrange them to form logical program segments. The following types of components are available for you to use when creating programs:

! [Input Contacts] (./LogicElementAndItsWorkingHeroies~/Images~/Input. png) | Input Contacts | Represents logical input conditions, used to simulate switches, buttons, internal conditions, etc. The normally open contact of the image is a type of input contact.

! [Output Coil] (./LogicElementAndItsWorkingHeroies~/Images~/Output. png) | Output Coil | Typically represents the logical output result, used to simulate lights, motor starters, intervention relays, internal output conditions, and other outputs.
! [Output Instruction] (./LogicElementAndItsWorkingHeroies~/Images~/Rectangle. png) | Output Instruction | Represents additional instructions, such as timers, counters, or math instructions.

The program segment is composed of the above elements and represents a complete circuit. The energy flows through the closed contacts from the left power cord (represented by a vertical line on the left side of the window in the program editor) to excite the coil or box.