Problem with SDC2150, motors stops after reaching certain encoder values

Hey

I am expirience a weird issue with an SDC2150 motor controller. The controller will run in close loop speed mode, seperate motor mode with max RPM around 100-200RPM.
Initially the PID controller caused problems due to the use of encoders with a too high resolution(approx 10000PPR), which was solved by using encoders with a smaller PPR. We have now approximately 500PPR on each wheel and the closed loop speed mode seemed to work fine, but not for long.
Whenever the encoders reach a count below -32000 or above 32000 the PID registeres a too high error and stop the motor. If we remove the error safety on the PID the wheels perform a tick-tock movement forward and backward showing a highly unstable system.
Apparently it seems the PID works with 16-bit values while the counter works with 32-bit causing a disagreement between them. It seems as the only explanation, but the question remaining is how to solve it? OR is the problem caused by another thing?
Another strange thing is the firmware, which is registered as released 5. December 2011(Rev 1.2-12/5/11), far later than the most recent firmware on the home page from October.

Regards

Sebastian Aslund

We are not aware of this problem. We will test here and let you know.

I have written you a direct request, but I might as well share the information here too.
The problem is in the speed measure unit of the roboteq controller. Within -32000 and 32000 the speed measurement reports a correct RPM value of the wheels. When the counter exceeds these values the speed measurement suddenly reports values 5-6 times higher eventhough the wheel move with the same constant speed as always. Afterwards it keeps stable around this high wrong value until the counter exceeds another value and jumps again.

I have tested it with two SDC2150\'s and the problem remained the same with the both of them. Changing the firmware to the one on the homepage did not change anything.

Regards

Sebastian Aslund

Problem is resolve in new firmware release

hello,
i have the same problem on my SDC2130-S.
when does the new firmware will be released?
thank you,

Hey Geva

I have a beta driver which solves the problem, you can give it a try. I only have the version for update through a serial interface.

Regards

Sebastian Aslund

Minor upload problems, here is the file

thank you for the quick reply!
is this firmware also for the -s version (single channel) controllers?

This is the very latest version of the single channel SDC2130 and SDC2150. This is beta firmware. Test extensively in your application prior to deploying. Pls report any issue found.

Ahh, missed that, mine is for the dual channel version :)