A test system 100 that can accept a plurality of plug-in electronic cards in Xi Slots 126 or PXI slots 134 is described. The test or source measure switching system 100 includes a sequencer or sequence engine 130 which is fully capable of executing opcode instructions having potentially indefinite completion times and monitoring multiple asynchronous inputs simultaneously without interrupts. The sequencer 130 is sequential and deterministic to approximately 10 microsecond resolution. The sequencer 130 includes a trigger router which can be a fully configurable trigger input and trigger output routing matrix. Every trigger input can be configured via several detection modes such as active high, active low, level high and level low. Also, trigger outputs can be configured to be triggered on single, multiple or auto triggers if set.