Elle_Man, Any chance you could give us an update on this problem?
I have recently been studying the PI-800 software and it looks like some of the settings will cause the cutting out at full throttle if you're using a potentiometer instead of a hall sensor throttle.
The "Throttle maximum allowed voltage" setting will be set somewhere between 3.8v and 4.8V as the hall sensor throttle has a maximum output signal voltage of ~4.5V. Unfortunately, the potentiometer's output will be as high as
5V (the +5V supply's full regulated output).
Therefore, turning the potentiometer to maximum would send a throttle signal voltage of ~5V to the controller, which is above the "Throttle maximum allowed voltage" setting. The controller would interpret the high signal voltage as a throttle fault and would respond by instantly shutting down the motor.
This important safety feature prevents full power from automatically being supplied to the motor if the ground lead on the throttle sensor brakes internally or somehow becomes disconnected.
I am now reasonably confident that the 1 MOhm potentiometer was the sole cause of the unusual throttle symptoms that you described in your last post.
I suspect that a 10K potentiometer would have given a much better throttle response throughout the majority of its travel, but it should still have cut the throttle before reaching it's maximum travel position.
It would be interesting to know if this was actually the case.
Also, Was David was able to sort the problem with the driver installation for the USB lead so that you could access to the various controller parameter settings?
Anyway, I really hope you were able to get things working properly in time for your project deadline.
Alan