angular encoder position measurement problem

[LucyXF]

I have a system which needs one pulse train generation (continuous) and two encoder measurements. The device I have now is USB-6211. I understand that there are only two counters available on this device and I can not have the task done with only one device. So I used another USB-6211. The program now can run without the "resource reserved" problem.

However, there's something wrong with the angular position measurement. This encoder signal is connected seperately on the other USB-6211, so it does not have any interference with other AI, AO, CI, CO connections. When the encoder is rotated clockwise, the angle measurement is fine. However, when the encoder is rotated counter-clockwise, the measurement is incorrect.

Could you please tell me what's wrong with my VI? Thank you very much.

[DavidMN]

Hi LucyXF,

For the pulse train generation, have you investigated using the freqout signal?  This would eliminate the need for two 6211s.  Information on how to program the freqout can be found in this KnowledgeBase.  If this does not help, try using the angular encoder task (counter input » position » angular encoder) instead of the count edge task.