For recording events from an external source, LabSat 3 is equipped with a digital input (DIGI) and digital output (DIGO) which can be found on the expansion connector at the rear of the device. Digital input is pulled up externally to 5 V. Digital out is a 5 V level output. To enable the digital input for recording, go to Menu > Setup > Digital > CH1 and then enable the tick against ‘Digi’ in the signal list. Then, during recording, LabSat 3 will also record the state of DIGI (pin3 of the expansion connector). During replay, the DIGO pin will output the recorded DIGI signal states.