This PmBinState field reports whether this bin's collection period completed normally, is still in progress, or was affected by a problem such as a device restart or a data gap. Because this row is a closed, completed interval from the PTP performance-monitoring history table for this timing session, State is what you check before trusting the counters in the row at all — a bin marked as partial or invalid means the accompanying byte/frame/error counts under-represent what actually happened and should not be compared directly against a normal full-length bin. For example, if this field reports something like 'partial' immediately after a card reset, you would discount the traffic totals in that same row rather than concluding traffic genuinely dropped to near zero.