Sampling a load cell and lvdt with Field Point

[acr]

Hi,
I have a load cell and a lvdt installed in an actuated system, which is basically a shaft that holds a weight on its end and goes up and down at a frequency of 1 Hz (1 second to complete the whole up and down cycle). This system is connected to a Field Point 2000.
I need to record and display a single stroke that lasts about 20ms. The single stroke should contain the variation of the load (and displacement) within the stroke duration (i.e., about 20ms).
I am having problems in choosing the correct acquisition time for such task and I think I am undersampling my measurement, but I am not sure.
I have difficulties in displaying the real time reading on a chart due to the wrong sampling and also, I am not sure if th
e way I am saving data is correct (I basically collect a bunch of points in a array and save those readings).

Could you please advise me? Also, please let me know if you need more information on my application.
Thanks,
Adriana

[Bill B]

Hello Adriana,

Thank you for contacting National Instruments.

FieldPoint is a single-point data acquisition system. This means that in software, you will want to try to sample as fast as your loop can iterate. If you have any type of delay inside your loop, remove it. This will allow your FP Read.vi to execute as quickly as possible. Since you need to acquire a samples within a 20ms window, you may not be able to acquire data fast enough to produce sufficient readings. You also need to make sure that you are downloading your application onto the FP-2000 using LabVIEW RT so that it is running as an embedded VI. This will improve your loop speed and allow more consistent measurements to be taken.

Regards,
Bill B
Applications Egineer
National Instrumen
ts