Logic Guide - AND (Built-in Functions, Function Blocks, and Conversions)

AND

Function Name	AND
Description	Outputs a Boolean value. The output is True if both inputs are true; if either input is False, the AND function has a False output.
Arguments	Input 1 to Input n {ANY_BIT} For more information on the data types for the inputs and outputs, see Data Type Hierarchy.
Returns	Output {Same data type as input} If any of the inputs is False, the output is False. The output is only True if each of the inputs is True.

Function Name

AND

Description

Outputs a Boolean value. The output is True if both inputs are true; if either input is False, the AND function has a False output.

Arguments

Input 1 to Input n {ANY_BIT}

For more information on the data types for the inputs and outputs, see Data Type Hierarchy.

Returns

Output {Same data type as input}

If any of the inputs is False, the output is False. The output is only True if each of the inputs is True.

Example:

Function Block Diagram - AND:

A Function Block Diagram has two Boolean inputs: FlowPresent and StopPump. The AND function only outputs a True value if both the FlowPresent and StopPump values are True. If either of the input values are False, the AND function outputs a False value.

ST Program - AND:

The AND function is used to provide a Boolean value that is only True if both inputs are True. The syntax for an AND function in an ST Program is:

Output := AND (Input 1, Input 2);

Where Output, Input 1 and Input 2 are defined as variables earlier in the ST program. Both Input 1 and Input 2 are Boolean inputs.