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Unread 17-02-2010, 14:49
mattbutts mattbutts is offline
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Potential Issue with the C++ CANJaguar Implementation

I have our Jaguars all running in CAN communication mode and the ones that are being controlled in voltage control are working great.

However, when I try to control a Jaguar in position control, I am getting garbage back from the encoder. I verified that everything was setup correctly by testing it with the BDC-COM utility. I can see the encoder perfectly there, and I can tune the controller and it works great.

We have a display for the encoder position on the driver station, and if I watch the value here it jumps around erratically (3 -> 8 -> 11 -> 65535 etc.). This makes me think it has something to do with the way the code is unpacking the data from the CAN messages, but I am not familiar enough with the messages to know that this is the case.

I guess my real question is: Has anyone else been able to get meaningful data back from a CANJaguar, and if so, did you have to do anything special? I really need to be able to get the position reliably.

Thanks,
Matt
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Unread 19-02-2010, 09:09
mattbutts mattbutts is offline
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Re: Potential Issue with the C++ CANJaguar Implementation

We were able to get it working. We believe that somehow the Jaguar was getting set to expect a potentiometer rather than an encoder. Not sure how though as we only had code in there for the encoder configuration.

Anyway, it works great now.
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Unread 19-02-2010, 13:26
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M.Rehberg M.Rehberg is offline
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Re: Potential Issue with the C++ CANJaguar Implementation

Would it be expecting an Absolute Encoder that outputs a 0-5 V signal based on shaft position? If you are working with a position control mode, that is what I would expect Vs using a relative quadrature encoder.

Mike R.
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