Actually, I've figured out how to do it with the Picoscope6 software and it works fine, but I can't seem to program a pulse width trigger using the EXT input.
I have a Picoscope4227. I've managed to program it using channel A as the trigger input... The programmer's guide also says that EXT input is ignored for the advanced triggering functions.
It just seems weird that it's possible in Picoscope6 but not when programming with the dll.
Played with the code a bit... I think it's a problem there. I'm using Python 3.3. I think the issue is with passing the structure to the C function.
Here's some pieces of code that work (ie no error) when I set trigConditions.channelA=CONDITION_TRUE, but gives a 0x22 error (PICO_CONDITIONS. One or more of the conditions are incorrect) when I set trigConditions.channelB=CONDITION_TRUE... even though channel B is enabled. I'm using dll version 1.1.0.288
Figured out the problem... I should have been using c_int instead of c_short. I guess it was trying to read the wrong memory segment or something. Everything works as expected now!