Build Lock-in amplifier with PXI-4461 4462

[jytang]

I would like to build a virtuallock-in amplifer as shown in youtube vedio https://www.youtube.com/watch?v=quiaXSAgocw.

So I purchased two card PXI-4461 4462 and intalled them in the system. I would like to output a signal from a AO in 4461, and input to AI of 4462 for measurement at given frequency. 

I downloaded the example from http://zone.ni.com/devzone/cda/epd/p/id/4532 which contain some subvi, but not so useful. Is anyone can help me to write a more useful example as shown on youtube? Thanks.

[Travis-E]

Hello Jytang,

Here is a link to an example that touches on Lock in Amplifiers:

http://zone.ni.com/devzone/cda/epd/p/id/4532

This uses DAQmx and was written with the PXI-4472 in mind but you should be able to get good functionality with the PXI-4461 and PXI-4462.

Regards,

-Travis E

[AussieRob]

Hi Travis,

I also am trying to develop a lock in amplifier but I find that a lot of links refering to this topic, to NI pages hace been removed or no longer available

Are the three vi's  (PLL .... Demodulator) that are used in the Lock in Amplifier Start up Toolkit still supported?

Are updated vi's available

There seems to be no support or interest from NI on this topic any more

[Mockingbird]

Hi Aussie,

The Lock in Amplifier Start up Toolkit was never really an official NI supported toolkit despite the name. It was released by a few people on our community pages as a free product to use that performed the functionality of what a Lock in Amplifier would do. Again, this was never an official NI supported toolkit so over the years the references to these VIs have been removed and they are not supported by NI. You might still be able to find the VIs by going through the forums, though, but these won't be updated and there is no support for them.

[AussieRob]

Hi Gabriel,

Thanks for your reply. Is there an alternative NI supported method for performing the equilivant to a lock in amplifier function

Thanks

Rob

[Mockingbird]

Hi Rob,

unfortunately, I do not know of any NI supported method for lock-in amplification. You might be able to build your own from LabVIEW VIs. Looking into the Sound and Vibration Toolkit, there are some VIs that let us extract single-tone information and multi-tone information, but I'm not quite sure how we could do that to build a lock-in amplifier.