The tag name for the First Scan Flag is what?

The tag name for the First Scan Flag is represented as S-FS. This flag is crucial in programmable controller systems because it indicates when the controller is performing its initial scan after a power-up or reset condition. During this first scan, specific initialization and setup tasks often need to be completed before normal operation can begin.

Understanding how the First Scan Flag functions is vital for designing effective control strategies, as it can trigger necessary actions such as resetting outputs or establishing communication with other devices at the startup phase. This ensures that the system is ready to operate under expected conditions, maintaining stability and reliability.

In contrast, the other options represent different flags or system statuses, but S-FS specifically signifies the first scan event, making it the correct choice in this context.