What is displayed below the tag of a SUB instruction related to its current state?

In the context of a SUB instruction within a programmable controller system, the value that is displayed below the tag indicates the result or output of the subtraction operation being performed. The SUB instruction is designed to subtract one value from another, and the output of that operation is crucial for monitoring the status of that instruction in real-time.

Displaying the value allows users to quickly assess the outcome of the subtraction operation, which is essential for debugging and validating control logic. By providing the current result directly beneath the instruction tag, programmers have immediate visibility into the state of their calculations, facilitating better understanding and efficient troubleshooting of the control processes.

The other options do not accurately reflect what is typically shown in this context. Source might refer to the input elements used in the instruction, while comparison usually pertains to operations that involve evaluating differences rather than merely subtracting numerical values. Control would relate to instructions that govern the execution flow, but in relation to SUB, it is the resultant value that directly correlates with the instruction’s current state.