This attribute records the reason the card test ended. It contains one
of the following values:
neverStarted: the card test has not been started.
testRunning: the card test is currently running.
testTimeExpired: the card test ran for the specified duration.
stoppedByOperator: a Stop command was issued.
targetFailed: the target card became non-operational.
becameActive: the source card became the active card for some LP.