USB 8451

[STEVEN_D]

Hi,

Does anyone know that the USB 8541 can write a 16 bit word and how?

Any help will be appricated.

Steve

[Chris_R.]

Hi Steve,

The USB-8451 only supports 8 bit transfers. You can still write a 16 bit number, but there will be a small delay between the 2 bytes (approximately 10-20 us).  This is a small delay and is typically not a limiting factor in your program.

The approach you would take when writing/reading a 16 bit number, would be to write/read a byte array of length 2.  You can use Type Cast to convert back and forth between arrays of 8 bit integers and arrays or 16 bit integers.

I hope this helps, but let me know if you have any questions!

[STEVEN_D]

Thanks.

I has been struggling with this issue.

I am writing the commands to program the AD9833. This chip takes 16 bit word.

Right now I have a few VIs that worked but it never gives me the desired frequency at the output of AD9833.

I did check the data. It read only the MSB and ignored the LSB.

Besides, I am new to Labview.

If you could, please send me an example (USB SPI 8451) that does this type of conversion, 8 BIT to 16 bit word.

Thanks again for your help.

Steve

[STEVEN_D]

Hi Chris,

I just wanted to know if I can write or read 16 bit word(command) at a time using USB 8451. If I can, please show me how.

[STEVEN_D]

Hi,

My partner had it working already.

Thank You

Steve