Millisecond Forums

Hello, 

I'm starting a new study which combines Cognitive Tasks, Polysomnography and ERPs.   I would like to use Inquisit for cognitive tasks that participants will be completing after a night in the sleep lab.  Therefore, I will need to send TTL signals from Inquisit into the SomnoMedics Domino system, which is designed to measure sleep EEG.

I contacted SomnoMedics and apparently the only hardware solution to interface these two software packages is to use a DC box to convert the output triggers from Inquisit into voltages which will be recorded as pulses of various voltage amplitudes in Domino, which I will later convert to stimulus/response markers.  

My question is, do different TTL signals convert to different voltages when sent through a DC box? For example, does a signal of 10101010 yield a different voltage than a signal of 10001001?   This is the only way I understand that it will be possible to differentiate stimulus in a way that corresponds with our EEG recording; unfortunately I don't have a way to test this as I currently don't have the hardware.