Rif.: Can I use NI 8451 for daisy chained SPI? How?

[Lesly]

Hi Experts,

I am new to Labview and now I am trying to find a solution how I can read and write SPI commands on a daisy-chained configured master-slave. The system I am using has 2 slaves. Each slave would need 24 bits per command frame and SCLK is at 400 kHz. Is it possible to use NI8451 for this problem? I would like to know because we would like to purchase this module if it can do the job.

I hope you can help me.

Thanks.

[tbob]

If you go to NI's website (ni.com) and search for USB-8451, you will find a lot of information about this device.  The user manual specifies that it has 8 chip select lines, so it can handle up to 8 slave devices.  The document shows how to hook it up and how to use it.  There is a Labview driver library for this device to make your programming easy.

[Lesly]

thanks for your reply. but this is a conventional SPI. I was asking if it is possible to use the USB 8451 for a daisy chained SPI configuration. In this case, there is only one slave select line for many slaves and each slave is connected in daisy chain.

[tbob]

If you have only one chip select line, how do you distinguish between the devices?  I have never used a daisy chain for several slaves so I don't think I can answer your question.

[Lucast85]

Hi Lesly,
I'm also new to Labview and I've your same issue. I'm studing for a custom test system and I would to use some SPI devices (ADC and DAC). Since the number of devices could increase in future, I think to use a daisy chain SPI configuration.
Are you been able to work properly with a SPI daisy-chain configuration and a NI8451 device?
Thanks in advance.

Luca Buccolini