BiSS Serial Protocol

[bmann2000]

Does anyone have any experience to share on the BiSS Serial Protocol ?  I'm considering interfacing to a BiSS encoder using sbRIO.

[Mark M]

Hi,

I hope you are well.

Do you have any more specific question?

[bmann2000]

I'm interested to know if anyone has BiSS FPGA G-Code to share.  www.biss-interface.com

It's an open-source protocol, so I figure someone may have posted G-Code for this application.  I'm also interested to hear of others overall experience of BiSS, limitations, advantages etc... 

[alexBC]

bmann2000,

I will get a BISS encoder next week and I intend to get the readings from the encoder by implementing a small portion of the protocol stack directly in G-Code.

Did you get additional feedback which you could share or have you already started with some type of implementation? Thanks

Alex

[bmann2000]

Hi Alex,  I eventually found a BiSS interface adapter from iC-Haus, it was £140 and iC-Haus have supplied LabVIEW drivers, I'm hoping it will be plug and play.  I've not started working with it yet, so I can't say how the drivers have been.  Here are the drivers.  http://www.ichaus.de/ftp/download/brianmann.zip

I bought the adapter from James Filmer, Product Manager, Semicom Visual Ltd, 44(0)1279 770400 www.semicom.co.uk  Beware, the power supply for the adapter comes with a German 2-pin plug, so you'll need a travel adapter.

I also found this product from addi-data, it's a multi channel solution:

http://www.addi-data.com/wEnglisch/redirect.php?http://www.addi-data.com/wEnglisch/produkte/pci_expr...

[alexBC]

Thanks for your help, but this will not give me a native cRio-FPGA solution. I need this because I am running a 50kHz Feedback Control Loop inside the FPGA and the position must be read with that speed.

[bmann2000]

I've not actually looked at the drivers yet.  I'm targeting sbRIO, FPGA commutating motor (field orientated control) with incremental encoder 50kHz, closing a rate loop with FPGA, then a position loop with BiSS encoder feedback using the processor 2kHz.  I may have to implement FPGA BiSS comms too, looks like you'll get there first.

[bmann2000]

Hi Alex, I starting on the BiSS interface to my Renishaw encoder this week, so far I've successfully configured the IC-Haus adapter, it's reading out 28-bits without any problem.  Next step is creating FPGA code to interface the Renishaw with a sbRIO.  Have you made any progress in creating this interface?

[alexBC]

Yes, I am reading out the angular position at a clock rate of about 100 kHz. You need a RS 422 driver, I am using a "DS 8921N" . The FPGA code takes very little space and coding was not very complicated because of similarities with the SPI Protocol. I am hesitating to post the code here because of patent and license issues, I am not sure if I am allowed to do that.

[bmann2000]

Hi Alex, thanks for the note on the driver chip.  I have similar code for serial comms I can use to get started, if I'm struggling I'll post my code here and maybe you can point out where I've gone wrong.  100kHz with minimal gates is a result.