How to review the perfect Trigger timing of the ActiveTwo system ?

If you want to check the timing delay between the analog inputs of the AD-box and the Trigger inputs of the USB box, you can do this by doing the following:

Make a 0-5 V square wave with a signal generator, connect to trigger input, connect attenuated version (resistor divider) of the same signal to ActiveTwo input (use the 2-bucket method as described in the Cortech manual)

Start acquisition in ActiView, go to on-line averaging, switch off all filters, start averaging, the zero sec mark is the moment that the trigger is detected, individual samples are indicted by points, you will see the second sample (first sample after the trigger edge) of the sweeps already reacting on the incoming voltage step.

See the below example of a 10 Hz square wave sampled at 512 Hz (speedmode 4, downsampled by a factor 4 in ActiView). The display shows the result of 25 averaged sweeps, proofing that both hardware and downsampling in software are perfect. First sample after the trigger is already rising, and exactly 5 samples are needed to settle on the high level (precisely as predicted by the response of a 5th order CIC filter). So, less than 2 msec (one sample period) delay and no jitter at all. The repeated average results allign exactly (no smearing). Indicating that there is zero jitter between the analog input signals and the trigger input.

This video (made by NEUROSPEC AG) perfectly shows how a trigger setup should be and what delays you can expect: Triggers -Presentation - Photocel