Lock in amplifier phase lock trouble

[GrantS]

Hello all,

     I've been trying to use a modified version NI Lock-In Startup Kit on some pretty simple AC signals. The VI is grabbing the signals from the DAQ card I have my PC hooked up to, I've been getting a frequency lock on the signals. However the phase and X-Y components seem to be all over the place. It's been kind of hard to troubleshoot the problem since I can't look at the PLL, demodulator and filter code. If anyone knows how to solve this and get a phase lock, that would be great.

Thanks,

     Grant

[GrantS]

scratch that, solved the problem.

[mallorim]

Hi Grant,

If you wouldn't mind, can you post what the solution to this issue was? That way, if someone with a similar issue searches in the future, they will benefit from your resolution.

Thanks,

Mallori

[GrantS]

I was testing the lock in amplifier (LIA) to see if it worked, and I was passing it signals from two function generators, one as a test signal the other as a reference. I thought to simulate real world, less than optimal conditions I could use two slightly different frequencies. It locked onto the test signal frequency, but the phase was all over the place. I realized that this was because of the frequency difference, which was probably a little bit too large to simulate real world test conditions that I would be using the LIA in. So I just made the frequencies from the function generators the same, and it began locking onto the phase difference. It was more a question of understanding how to work the LIA than a coding problem. Hope this helps.