How do I get my SCB-68 and PCI-6025E to do quadrature encoding?

[BCrawford]

Hello,

I am currently running LABView 8.0 and have the PCI-6025E and SCB-68 cards.

I am trying to do quadrature encoding in two different points of interest and have set up two simple counters that count up and down. For some reason when I hooked up my SCB-68 the counters only counted up. I don't think that the error lies in the code so I am starting to think that this card is not hooked up correctly.

I have the counters going to channels 37 and 16 for one and the other is 42 and 48. When I bought this card it had been modified by the previous owner and I had to remove some of the additions, but since I am not really using the analog inputs do I really need to remove it all?

There is a chance that my code is not set up correctly so any input would help.

Thanks

[JB]

This document shows how to use a quadrature encoder with a Series E DAQ board.


As mentionned in this document :
...Wire Channel A output of the encoder to the SOURCE input of the DAQ-STC and wire Channel B output of the encoder to the UP_DOWN input. Notice that the UP_DOWN input is accessed on the P0.6 pin for counter 0 or P0.7 for counter 1.

Figure 3 on page 14 of the specifications shows that the pins for a PCI-6025E are :

• CTRO :

• A --> 47
• B --> 30

• CTR1 :

• A --> 41
• B --> 32

You might also be interested in this DAQmx example.

[PBear]

Hi BCrawford,

Please note that the quadrature functionality on the E-series DAQ devices only allow for basic functionality. For more robust counter/quadrature applications, consider our M-series line of Multi-Function DAQ products as they support digital filters and Z lines (amongst other things).

Just something to take note of while developing your application.