How are self-test faults displayed on the indicator?

Self-test faults are displayed on the indicator using the letter "F." This symbolizes a failure in the self-test, indicating that the system or device has detected an error or fault during its diagnostic procedure. The use of "F" is a standard convention in many technical systems, serving as an immediate and clear notification that something requires attention.

The other options do not communicate faults effectively: "X" may be used for a variety of purposes depending on the context, "0" might denote a neutral state or no faults detected, and "Pass" suggests that everything is functioning correctly. Thus, when troubleshooting or assessing the status of a system, recognizing "F" as a fault indicator allows for quick identification and response to potential issues.