Angular Position with a Quadrature Encoder, PCI-6621 & PCI-6052E

[Steve289]

I have a feeling that there is a simple explanation to this question but I cannot find it.

I need to measure Angular Position using a Quadrature Encoder.  I have no problem doing this with a PCI-6221 or a PCI-6601 but I cannot get my PCI-6052E to do this.  When I try and create a virtual channel using max for the PCI-6052E I am told that there are no supported devices.  Am I correct is saying that both of the boards have up/down counters (6052E is a lower resolution than the 6221).  What spec would tell me wether or not a board that has counters is capable of measureing angular position so I can accuaratly make dessicions on futre DAQ projects.  I also wanted to do this task with an USB-6009 but the general purpose counter is not capable of counting up/down right?  Is this a Max bug and I need to use channel propery nodes to manually assign the encoder channels to the proper counter pins?  I just don't want to make assumptions in the future thinking that becuase a board has up/down counters it will be able to measure angular position.

Thank you in advance for your responses.

Steve 

[Kevin_Price]

I'm not from NI so don't take this as final official word...

1. Generally speaking, the 660x series counter/timer boards and the M-series multifunction boards are the primary devices that support quadrature encoders in hardware.

2. E-series boards' counters can be used if a simple interface circuit is built between the encoder and the board.  You can search here for more info on the LS-7084 quadrature conversion chips.  Other good keywords include "E-series", "quadrature."

3. Even without an interface circuit, E-series boards can do some encoder measurements.  Period measurement determines speed, and you can also wire up a "poor-man's quadrature" that will sometimes work perfectly and usually work pretty well.  Depending on your particular app it may be good enough, though the 7084 chip would be more robust.  You can read more here.

4. NI recommends consulting with a sales engineer when considering a purchase.  That should also help make sure you don't get stuck with under-powered hardware.

-Kevin P.

[McKala[DE]]

Hello Steve,

What Kevin said was right on.  I wanted to add that NI doesn't support the use of angular encoders with any of our E-Series boards.

Regards,