Having found that I'd need to be accessing XInput functions I was able to narrow down what I needed to search for and eventually reached this:
http://hutonggames.com/playmakerforum/index.php?topic=11129.0It's a Playmaker action that can enable rumble on XInput-compatible controllers. Unfortunately either it's a bit basic or I'm doing something wrong with it as while I can get the pad I have connected to rumble with either motor, I have very little control over how long it lasts, nor does the action ever seem to end so the FINISHED transition is never called.
Has anyone seen this and had any success using it, or is there a better action out there?
Edit: Being a bit lazy I probably should have experimented a bit more and thought about the problem before posting. Here's what I'm doing...
1 FSM that is applying the rumble effect to controller 0
1 FSM that changes the values of float variables in the FSM above.(On/off, left motor, right motor)