I don't actually think it isnprobably very important to specifically state it is a 'voltage', so I think 'signal' would be the better way to express it; and I don't honestly see why they add the word 'trigger', it seems singularly redundant to me — unless perhaps they simply intend to imlply thereby that it is merely a one-off pulse? In which acse, maybe 'impulsion de commande' might be better?

It would probably help a bit to understand more about the technical details of the actual system employed.