Re : NI USB-8452 CS in stream mode

[ibvp_ss]

Hi,

I've recently bought a NI USB-8452 device and taking a look at the Stream mode I cannot figure out how to modify the chip select number. Looks like during the streaming it is only possible to use the CS0. Is there any option for using a different chip select with the Stream Mode?

Thank you and best regards

[Julien_31]

Hi,

I am not familiar with this hardware but this could help you :

http://www.ni.com/pdf/manuals/371746e.pdf

Please see chapter 14 - page 4 (§ Chip Select) :

The Chip Select (CS) pin is commonly used to signal an SPI slave that your
NI 845x device is intending to communicate with it. When the CS pin is
configured as Active High, Active Low, Drive High, or Drive Low, the pin
is configured as an output using CS0.

Hope it helps...(?)

[ibvp_ss]

Thanks Julien. That is actually the problem I want to solve. It takes CS0 by default and I can´t find how to modify for using another CS line.

[rkmadse]

I believe that because the CS in streaming is hardware-timed and can only be implemented in hardware and isn't something you can change.

Page 45/524 of the manual: 

"1 You can configure CS(0) as hardware-timed chip-select, which has a fixed timing relationship to SPI signal lines. Refer to Chapter 14, Using the NI-845x SPI Stream API, for details."

So it looks like you can only "stream" to one device, but in basic mode you can talk to 8.