	_ports	Desired output ports. Can be a constant or a variable, see Output port constants. If you use a variable and want to control multiple outputs in a single call you need to use a byte array rather than a byte and store the output port values in the byte array before passing it into this function.
	_pwr	Output power, 0 to 100. Can be negative to reverse direction.
	_turnpct	Turn ratio, -100 to 100. The direction of your vehicle will depend on its construction.
	_reset	Position counters reset control. It must be a constant, see Tachometer counter reset flags.