What PLC program instruction is responsible for making decisions based on data values?

The decision-making capability within a PLC program is primarily executed through comparison instructions. These instructions evaluate data values against one another or against specific set points, enabling the program to determine which path to follow based on the results of these evaluations.

For instance, a comparison instruction might check if a sensor's value exceeds a threshold or if two values are equal. Depending on the outcome—true or false—the program can direct the flow to different sections of the logic, perform actions, or change outputs based on the conditions defined.

Other instructions like MOV, ADD, and SUB are used for data manipulation, such as moving values, adding numbers, or subtracting values, but they do not inherently enable the controller to make decisions based on those values. As a result, comparison instructions are crucial for implementing control logic that responds appropriately to varying inputs in a PLC environment.