TB sensor version also include a self-teaching process launched after yarn tension goes below 80g and then stay over 120g. During self-teaching process, MYT-TA or TB records tension to set a reference level. There are 2 level of windows. One for short response time (0,4s) but with wider window (±30% of reference level), and one for normal response time (2s) but with smaller window (±12% of reference level). When yarn tension goes out from predefined windows, MYT-TA or TB NPN output delivers a LOW level signal to the machine to stop position or to drive a yarn cutter.