Using more than 4 quadrature encoder input for MyRIO

Question

Hello,
I am doing a project where I need to drive 6 motors, each with quadrature encoder feedback to control position. 
Currently, I've been using the MyRIO Encoder VI's, but there's a limit to 4 encoders. What is the best way of reading 6 encoders simultaneously with the MyRIO?
Thanks,
Timothy
Solved!
Go to Solution.

Answer 1

If you need to modify the myRIO FPGA personality you have a few options.
The best option is to start with the myRIO FPGA sample project, add and remove components as needed and then build your bitfile.  Any registers (LV FPGA controls / indicators) you don't modify will still work with the Advanced IO VIs and Express VIs.  In order to use the new bitfile (FPGA Personality) you'll need to update the Open FPGA VI Reference in myRIO v1.1 Open.vi (LabVIEW 2013\vi.lib\myRIO\Common\Instrument Driver Framework\myRIO v1.0\myRIO v1.1 Open.vi).
After doing this any time you use a myRIO Express VI or Advanced IO VI it will use your custom bitfile.  Any peripheral channels you've left in place will continue to work.  Any channels you've removed will still show up in the VIs, but will not work (they will probably throw errors at runtime) and any new channels you added will not show up in the VIs.  For new channels you'll need to use the FPGA Read / Write nodes to read and write the configuration and data register you created in the FPGA personality.  These changes will persist on that computer until you change the Open FPGA VI Reference back to the original bitfile.
Let us know if you have questions about any of this.
Thanks!
-Sam K
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