As I had mentioned previously, you need to properly set up a
<port> element to send triggers to external equipment such as NeuroScan. Thus:
how to know which port to use (LPT 1 or LPT2)
You use the LPT port Neuroscan is connected to on the PC. Either
/ port = LPT1
/ port = LPT2
and is there anything to be set in the Inquisit software to enable this triggers to be sent
The 8-bit TTL signal to be sent is defined in the <port> element's /items attribute. For the specific signal NeuroScan expects as well as other NeuroScan-specific settings (e.g. the subport to use) refer to the NeuroScan documentation.
/ items = ("00000001")
Once this is set up properly, you need to send the trigger out at the desired time via your <trial> elements' /stimulustimes or /stimulusframes attributes. E.g.:
/ stimulusframes = [1=myvideo,onsettrigger]
You may test connectivity between Inquisit and NeuroScan by using the Parallel Port Monitor tool.