In LAD programs, the basic elements of logic are represented by contacts, coils, and boxes. The set of interconnected elements that make up a complete circuit is called a program segment.

Contact symbols serve as inputs for program circuits. The series and parallel connections of contacts are equivalent to the series and parallel connections of circuits, as well as the AND and OR operations of logical expressions.

1. Normally open contacts enable energy flow when the parameter is set to TRUE, and disable energy flow when the parameter is set to False.

2. Normally closed contacts are the opposite, enabling energy flow when the parameter is set to False and disabling energy flow when the parameter is set to True.

3. Rising edge contact and falling edge contact enable energy flow only once during the rising edge event of the parameter, and turn off energy flow in other situations.

4. Compare two parameters of the contact point, enable energy flow if it meets the conditions, otherwise disable energy flow.

The coil symbol serves as the output of the program circuit.

1. The normally open coil outputs a parameter of TRUE when the current passes through, and outputs a parameter of False when the current does not pass through.

2. The setting coil is only executed when it can pass through, and outputs a parameter of TRUE within the range.

3. Reset the coil only when it can pass through, and output the parameter within the range as False.

The box serves as the execution symbol for program operations and, like the coil, serves as the output of the program circuit, determining whether to execute based on the energy flow.

FBD program elements are represented by boxes. AND/OR boxes (gates) can be used to process Boolean signals in the same way as ladder diagram contacts.

STL program elements are represented by a set of instructions that perform functions. STL programs do not use the graphical display used by ladder diagram programs and FBD programs, but display in text format.

Show different representations of equivalent logic in the following examples.

Command table:

NETWORK 0

LD M0

AND M1

OUT M2