How about using labview's filter vi and multiply vi to replace the analog filter and amplifier

[g_l_g_s]

Dear all,

I am using a DAQ system to acquire a weak signal, it seems that a low pass filter and voltage amplifier are needed before DAQ. I am wondering, if I use the labview's low pass filter vi and multiply vi to process the signal captured by DAQ, can I get the same effect as analog Low pass filter and amplifier?

Thank you!

[johnsold · Accepted solution]

No!

1. Any sampled data sytem must be bandlimited before sampling to avoid aliasing.  It is impossible to remove aliasing after sampling.

2. The resolution of the DAQ system will be so low that you will have very "coarse" digitization and you will lose much of the information in your signal.

Sorry, but you must amplify and filter in hardware before the DAQ device to get good results.

Lynn