This field records how much the counter for FCoE frames that failed to be transmitted correctly out this interface increased during the most recent collection interval, rather than the lifetime cumulative total. For a network admin, this is the transmit-side counterpart to errorsRx, and a steady climb suggests an adapter or fabric-interconnect-side problem originating from this blade rather than from the far end. For example, 5 frames in the last interval on this specific FCoE path would already be worth a closer look, since this counter should normally sit at or near zero.