AX2850 Encoder Data Corruption Issue

Hello all,

I am using MATLAB to constantly query the encoders to update dead reckoning info in my program. Occasionally, the Roboteq will send back a corrupted response. The response always has \"OK\" in it. Here is an example of the output (from a serial port monitor):

Request:
?q4.?q5.
Answer:
?q4.34.?q5.69. (<--good answer)
Request:
?q4.?q5.
Answer:
?q4.0A4.OK. (<--BAD answer)

Request:
?q4.?q5.
Answer:
?q4.0.?qOK.W (<--BAD answer)

This happens at random and I am not sure what is causing it. Am I possibly not allowing enough time for the Roboteq to respond? Any ideas?

I don\'t think the roboteq is switching modes when this occurs, because after a bad response, i continue to see the watchdog \'W\' implying that it is still in 232 mode.

any ideas short of splitting my data cable off to an additional computer?

Thanks

-Ben

Chances are at 99% that the controller is sending correct data and that characters are lost in the transmission or in the PC com port receive function.

FYI, roborun queries this information all the time and is particularly vulnerable (ie it crashes) if it gets incoherent data. Yet, it never crashes.

Well, it sounds like there probably isnt much I can do about that then. Damn. The problem is the fact that the encoder values are cleared each time I read them (in relative mode), so my travel information is lost any time this occurs.

thanks everyone.

-Ben