6120 encoder

[Rob B]

I am trying to measure and log an encoder.  I understand the 6120 can make encoder measurements, but I can't create a task in MAX.  I can select ctr0 & ctr1 in MAX under Acquire Signals >> Counter Input >> Edge count, but MAX doesn't show the 6120 if I select Counter Input >> Position >> Linear or Angular.

Is there a reason for this?

If I can get this working what is the max sample frequency for the encoder?

Rob Benjamin

[Corby_B]

Hello Rob B,

Thanks for your post!

I see that you are wanting to use the 6120 to do either Linear or Angular counter measurements. Unfortunately those are both unsupported on the 6120. The measurements you can perform are

Frequency,

Period,

Pulse Width,

Semi Period,

Count Edges

You can find this information in the S-Series Users Manual Page 7-12. See the following link for the S-series Users Manual. If you are wanting the MAX frequency it depends on the way you are using the counter. If you are using 1 counter in your task then the most accurate results are about 1/4 of the time base you are using to count with. In the case of this card that would be the 20 MHz time base. For higher frequencies and larger ranges use two counters. You can select these when setting up your tasks in MAX. This board has a minimum input puls width of 10ns for using counters. Let us know if this address your concerns/questions and have a great day!

Cheers!

Corby_B

http://www.ni.com/support