This flags whether the DS0 far-end test has achieved pattern synchronization on this channel; the test pattern must be detected four consecutive times to sync, and this variable is set to 1 if that sync is subsequently lost. Losing pattern sync partway through a test on this specific channel invalidates whatever error counts have accumulated since the loss, since the receiver is effectively comparing against a misaligned reference, so this flag tells you whether pportDS0BitErrorCount for this run can actually be trusted. If this shows 1 midway through a scheduled test on this channel, any bit errors counted from that point forward should be disregarded until sync is confirmed to have been reestablished.