This reports whether this specific output is actively and validly distributing a timing signal to downstream equipment right now, as distinct from the quality level it's advertising. An admin troubleshooting a downstream device that reports no timing signal at all, rather than just a degraded quality, should check this object first to confirm the local output is even active before investigating cabling or the downstream device itself. For example, this object reporting a fault or inactive state would explain a complete absence of signal at the downstream device, pointing the admin at this device's output rather than the cable or the far end.