different acquisition time in the same time

[quanti]

Hi
I want to acquire a signal from an accelerometer, in real time, and in the same time i want to acquire a signal from thermocouples every 15 sec.
I dont have the choice to use the same Ai components, if not I have an error from the buffer. I tried different things and i'm not able to solve it. Do you have an idea or an exemple of how I can solve this problem ?

I'm using the sc-2345

Thanks a lot

[Ahmed Khwaja]

Hi,

You can first get the acceleration and then get the temperature. Since temperature transducer does'nt chnage instantaneously(i.e. with couple of seconds), so you can manage to get both the readings at the same time.

[Sastry V.]

What type of hardware are you using to measure the the signal accelerometer? In order to measure the accelerometer data as well as the temperature data, you need to write code in such a way that time sharing is done. I would suggest you to take a look at examples related to Multiboard Analog input.

Sincerely,
Sastry

[Bryan F]

Hello --

I've attached an example that illustates hardware synchronization between a PXI-4472 and PXI MIO device. The code allows the board to maintain tight synchronization but run at different sampling rates if desired. (I don't know if you are using a DSA product like the 4472 for the accelerometer measurements -- it is a very good acquisition board for sound and vibration).

If you are using only one board, you will not be able to acquire single points on the thermocouple while a continuous acquisition is in progress for the accelerometers.

Two possible workarounds come to mind. You could stop the accelerometer aquisition, grab a temperature point, and restart it. This is a bit awkward, so you could also just define 2 channels in your sca
n list and acquire both the thermocouple and accelerometer continuously. You would get lots of excess data for the thermocouple, but it should be straightforward to use array manipulation to disregard all but a small fraction of it.

Bryan