Hi,
I am not sure about the NI-6713 that you mentioned since that is the name for an analog output board. But that's fine! Whether that is a typo or you intended some other product, I have a few ideas that you could use.
Two products that you can look at are the NI-4060 (High Resolution DMM) in combination with an SCXI-Switch module, and an E-series data acquisition board in combination with an SCXI signal conditionaing module.
The first option is the NI-4060. It is a high resolution DMM so it has one channel of measurement. The reason for having one channel is that the NI-4060 is intended for use with a switch that can provide very configurable and expandable multiplexing options. You would probably use the SCXI-1127 or SCXI-1128. With one one of these modules
, you can switch or multiplex between 32 differential channels.
For a 20mV range, you will get an accuracy that in short, is about +/-8 microvolts. For a better description, you can look at the
user manual for the NI-4060.
Another option is a high resolution e-series data acquisition board (for instance the PCI-6052E) in conjunction with a millivolt signal conditioning module (for instance the SCXI-1102B). The combination allows you to use a standard data acquisition board, lowpass filter your signals, and apply a gain so that the signals are not as susceptible to noise.
For the software, I think LabVIEW is a great choice. If you prefer text-based programming, you could go with Measurement Studio.
I hope these give you a starting point for finding what you want. Other people might have different suggestions for you, and I'll try to answer questions if you want to reply to this post.
If you want help configuring a sy
stem, one of our internal sales folks might be able to help you even more with picking parts.
Take care and good luck,
John N
National Instruments