You'll need to do some tests to see if it is possible. You'll have to consider the nyquist theorem. There have also been discussions here regarding the speed at which acquisition is possible. If you are simply using analog reads, the speed will be dependent on your OS and other programs that are running including the speed of communication with the Arduino.
Depending on how many samples you want/need, you might have to consider using the continuous acquisition functionality (this will be able to sample considerably faster than using a simple analog read in a loop in LabVIEW). So, I would recommend that you find some threads regarding acquisition speed possible.
EDIT: I just realized that you are trying to read three signals. This would not be possible with the continuous acquisition functionality.
Also, given that you are reading three signals, it will be three times slower than reading just one. If you consider the that a LINX (LINX is faster than LIFA) packet will be approximately 4ms, you will need at least 12 ms to get a single reading for your three signals. That will allow you to get at most about 84 Hz which does not satisfy the nyquist theorem for a 100 Hz signal.
