6120 incremental encoder / quadrature input

[L. Klaus]

Hello,

I'd like to measure an incremental decoder with the PXI-6120. About the same question was already asked before:

http://forums.ni.com/t5/Multifunction-DAQ/6120-encoder/m-p/776882/highlight/true#M43023

In the answer to the question is stated, that this is not possible.

On the other hand, in the specifications of the PXI-6120, the encoder input is listed (see specifications - Measurement Type Digital, Voltage, Frequency, Quadrature encoder😞

https://www.ni.com/en-us/support/model.pxi-6120.html

I tried to use this feature (Labview 2010 DAQmx and with creating virtual channel in the measurement explorer), but an error occurs, stating that the device is not supported. How can I use this feature?

Best regards,

L. Klaus

[Christian Mergl]

Hi,

The 6120 does not support quadrature encoder tasks.

I'm wondering where you found it in the specifications since the even phrase "quadrature" couldn't be found. Could you point me the the manual and the exact page where you found it.

Christian 

[L. Klaus]

Hello Christian,

if I go to 'Specifications' at the second link in my post, I can find under 'Mesurement Type' -> Quadrature encoder, Digital, Voltage, Frequency. To make it a little easier, I attached the PDF-printout to this post (see page 3 in this PDF).

Hopefully this helps.

Best regards,

L. Klaus

[Christian Mergl]

Since the 6120 is using the old STC counter chip it does not directly support quadrature encoder tasks.

However, you should be able to get it run as described in this KB, which actually refers to E-Series but it should be the same for the 6120.

Christian

[L. Klaus]

Hello Christian,

thank you for these informations. I still wonder why NI advertises this feature on the specifications-website of the NI 6120 card although it is impossible to use it directly.

I will try using the timers for quadrature-encoding as described in the linked document.

Best regards

L. Klaus