Ladder Logic is a graphical programming language that represents a program in the form of a ladder diagram. It’s based on relay logic and was initially developed to mimic the logic used in traditional relay control circuits.PLC (Programmable Logic Controller) LS often refers to the “Ladder Logic” programming language used to program PLCs.
The specification of a PLC’s LS typically includes the following components:
Input Instructions: These represent the conditions that need to be met for the PLC to perform certain actions. Inputs can be physical (sensors, switches, etc.) or logical (status of other components).
Output Instructions: These indicate the actions the PLC will take if the specified conditions are met. Outputs can be signals to actuators, motors, or other devices.
Relays, Timers, and Counters: Ladder Logic allows the use of relay-like functionality such as timers and counters. Timers can introduce delays or control the duration of an action, while counters can keep track of events.
Logical Operators: Ladder Logic supports various logical operations like AND, OR, NOT, etc., allowing for complex conditions to be specified.
Mathematical Functions: Some PLCs support mathematical functions to perform calculations within the ladder logic.
Special Functions and Instructions: PLCs often come with specific instructions and functions for handling specific tasks, such as PID controllers for regulating processes or communication protocols for interfacing with other devices.
