Alarms are a key component of Teradyne’s test systems. They indicate a hardware condition caused by a bad device, an incorrectly programmed instrument, or a test system failure that may invalidate a measurement, potentially causing a bad device to be sorted as a bin1. The UltraFLEX tester family has implemented a fully-integrated Alarm Service that ensures hardware alarm conditions are monitored, filtered, reported and processed properly without requiring additional user code to the test program. The user can then choose to have the device binned either to the fail bin associated with the alarming test or to a dedicated alarm bin. The UltraFLEXplus and its PACE pipeline architecture introduced nuances in the way alarms are handled. This presentation will describe how the alarms reporting and processing work, present different debugging tools and review best programming practices.