Victor + CIM Motor = Jumpy when Negative (Reversed)

[dwmcc]

Hello All,

Thanks in advance for any and all help on this issue.

We're using Labview with all updates installed, and our robot drives perfectly.
We have a Victor hooked up to PWM 3, and then to a CIM motor. In Labview, we have two True/False bracket that are separately hooked up to two different buttons from the Joystick. If Button 4 is true, it sets the Victor speed to 60. If it is false, it sets the speed to 0. In the other T/F bracket, it sees if Button 5 is true, and sets the Victor speed to -60. If it is false, it sets the speed to 0. The thinking is that if you press one button, the motor goes forward, and if you press the other, the motor goes backward. If no buttons are pressed, the motor is idle/stopped/set to 0.

Here's where it gets weird: If you press button 4, the CIM motor spins forward perfectly. If you press button 5, the CIM motor does not spin backward, and sometimes jumps backward (in reverse) in small increments. What the heck? The code should tell it to go in reverse just the same as it should have gone forward.

Now, we only have one T/F bracket, and we put, say button 4 (if true) to -60, and if false to 0, the motor spins in reverse perfectly.

The two T/F brackets are not connected, and shouldn't be influencing each other, right?

Any suggestions? We're stumped and haven't found any other problems like this on cheif delphi.

Thanks,
dwmcc
Team 2192 Programmer/Web Design/Electrician