Encoder readout speed of 9512 module

[sodupuc]

Dear all,

I would like to read encoder position (encoder connected to 9512) of stepper motor (also connected to 9512 module and P70530 driver) operating in closed-loop mode at speed higher than the scan engine speed (default 100 Hz, 10 ms). I have cRIO 9025 and FPGA chassis 9118. Is that possible with soft motion? If I change the speed of the control program running on RT cRIO (timed loop at 1 kHz), the encoder output is updated at loop rate, but the data output reflects still the scan engine speed. If I change the speed of scan engine on RT cRIO to 1 kHz, I get an error.

Another idea would be to program the 9512 module in FPGA mode, but as I understand, you have to synchronize FPGA to scan engine... 

So my question is: Is it possible to read encoder output data at speed higher than 1 kHz with 9512 stepper module?

Thank you!

[sodupuc]

no one knows?

[BalazsNagy]

Dear sodupuc!

Sorry for the late reply.

First of all let's have a look on the 9512 FPGA Interface: http://zone.ni.com/reference/en-XX/help/370984T-01/target4devicehelp/9512_io_reference/ 

Using the read method you can read the encoder position: http://zone.ni.com/reference/en-XX/help/370984T-01/target4devicehelp/9512readmethod/ 

You can use the SoftMotion with Scan Engine: http://zone.ni.com/reference/en-XX/help/371093M-01/mclvhowto/infoiowscaneng/ 

AND

in FPGA mode as well: http://zone.ni.com/reference/en-XX/help/371093M-01/mclvhowto/951xfpgamode/ 

I guess you were following this tutorial when creating your application in Scan mode: http://www.ni.com/white-paper/9666/en#toc8

Please find hints and descriptions how to use 9512 in FPGA mode with SoftMotion, so you could read the encoder signals with a faster rate than Scan Engine update rate:

How Do I Use the NI 951x Drive Interface Modules in FPGA Mode: http://digital.ni.com/public.nsf/allkb/B0B5A8EB811D5AF3862576B90058921D?OpenDocument 

But the most information is written in the manuals, that you can find on the Softmotion"s webpage:

Getting Started with NI SoftMotion for SolidWorks: https://www.ni.com/docs/en-US/bundle/372876e/resource/372876e.pdf

Using the NI SoftMotion Axis Interface: http://www.ni.com/pdf/manuals/372597a.pdf

(On the 10th page you can see a complete example) 

LabVIEW 2012 NI SoftMotion Module Help: https://www.ni.com/docs/en-US/bundle/371093k/page/download.html

If you would like to use your ready application, and implement only the encoder functionality on FPGA, please go through the following:

How Can I Use Scan Engine and FPGA Simultaneously on a CompactRIO (Hybrid Mode): https://knowledge.ni.com/KnowledgeArticleDetails?id=kA03q000000YIDfCAO&l=en-US

Error -65536 When Using Scan Engine and FPGA Simultaneously on a CompactRIO: https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000PAjWSAW&l=en-US

Please find below the link to the CRIO Developers Guide, which I recommend to everyone who would like to develop successful applciations for CRIO.

https://www.ni.com/en/shop/compactrio/compactrio-developers-guide.html

Some examples: 

https://forums.ni.com/t5/Example-Code/NI-CompactRIO-Dual-Axis-Sun-Tracker-Example-Design/ta-p/398371...

Please search in LabVIEW Example Finder for examples as well. (LV >> Find Exmaples.. >> Search for 9512 or for Softmotion)

I recommend the Stepper interface (9512).lvproj to go through.

I hope you will find the attached resources useful.

Best Regards,