However, for some special cases, if scanner fires laser under certain ”short firing pattern” continuously, it will keep holding IBIS algorithm from initiating the reset and ends up the P3 PZT voltage hits the hard track threshold due to lack of room for the soft track. Once the hard track is initiated, it could happen at any time even during wafer exposure, which leads to a BQ and KI-0201 (Too Many Beam Quality Faults Per Wafer) or DC-1815 (BQ Low Exceeds BQ Error Level) eventually.