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G2 21v3 - motor oscillations

I have a 21v3 driving a 12v DC motor through 90 degrees.

My feed back is a voltage based sensor (0-5v).

Control setpoint is from PC at this stage.

Using the manual to setup the motor drive direction etc is fine and I am able to set up feedback correctly(positive with motor forward)

But when I run with feedback the motor moves to setpoint then oscillates around setpoint.

My status screen is

my setup screens are;



What is causing the oscillations?


You are emailing with us as well, and have followed-up with us there. For others who might come across this thread, it sounds like you were able to reduce or fix the oscillations by further tuning your PID coefficients, which sounds reasonable. We have some general suggestions for tuning the PID coefficients in the “Setting Up Your System” section of the Jrk G2 user’s guide.


Quick followup after some playing and help from Brandon.

To make it run fairly well and stop oscillating I had to drop proportional number right down.

Give or take it is there now with analog feedback and control.

This controlling a set of motorcycle throttle bodies.

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