Originally Posted by nvocc5:
Quick question to expand my knowledge what application is the "active Hi" mode used for ?
That's a deep question with a combination of historical, by-convention, and technical roots. I'll give a politicians weasel answer by saying that the "active Hi" mode is used when you want to trigger/activate something using a hi level signal rather than a low level signal. Both methods are used in electronic applications. Next question. 
Originally Posted by ken's trains:
I tried every possible combination of + & - VCC and trigger (of course except the one that worked).
As you saw for yourself with the timer module, the instructions (if any are provided) can be incomprehensible.
