Low sampling rate with USB-8451

[henria]

Hello,

I'm relatively new to LabVIEW, and I'm trying to make LabVIEW communicate with Anolog Devices ADIS 16210 via NI USB-8451 and SPI.

I've succeded in getting inclinometer and accelerometer data out, but I'm struggelig with very low sampling rates. It looks like new, updated inclinometer and accelerometer data is only accessible once each second, meaning that the effective sampling rate is 1 Hz.

The attached VI contains a set up demonstration.

I would appriciate some help!

-H

[mikeporter]

Do you mean?:

A) You only see the value change once per second

or

B) That it takes 1 second to read the output (the loop is only looping once per second)

Mike...

[henria]

I mean

A) I only see a value change once per second.

I've also written the data to text file, and apparently it's writing new values only once per second.

The loop is definiteley looping more than once per seconds, as I've added a test waveform and a controller to it. This one updates in near real-time.

-H

[mikeporter]

That chip can do a lot of onboard filtering and averaging to smooth the output. Combine that fact with your observation that the loop is running more than once a second and it could be that this is just how long it takes the device to recalculate a new output reading. It looks like you can reconfigure the chip, but the output will get noisier too.

Mike...