Lock-in Amplifier and DAQmx

[Rob M.]

I've downloaded the NI Lock-in amplifier toolkit (llb file), and I have
a PXI-4472 board. The toolkit looks to be based on traditional DAQ, not
DAQmx. Did I miss the DAQmx version, or has no application engineer
posted one yet? Please let me know if there's a timesaver out there
before I just start to convert it on my own.
Thanks,

Rob

[Travis W]

Here is the Lock-In Amplifier example library for NI-DAQmx.  This will go live as an EPD on Tuesday.

Thanks
Travis


MultiChannelLockIn-DAQmx.llb:
http://forums.ni.com/attachments/ni/100/938/1/MultiChannelLockIn-DAQmx.llb

[Rob M.]

Thanks. That version doesn't work with LabView 7.0, by the way. I had a tech support person email me with a version that would.
Here's an update from my end: I have it setup and running. Only, it seems to burp at the PLL sub-vi. I KNOW that have the correct data going into that sub-VI and that my DAQ board is working b/c I've put probes and indicators in the path and such. The problem is that it doesn't calculate the correct reference info. If I place a probe at the "reference info" output, it returns a constant output of fr=1 and phase =0. This is bizzare. I've changed every parameter I can think of (sampling rate, block size, offset parameter, column value, time constant, etc.) but it yields no positive result.
Any ideas or suggestions? I'm at wits end.
BTW, my board is the 4462, not the 4472 I mentioned previously. And, my refrence signal is a TTL square wave from 0-4 Volts, operated anywhere from 10Hz to 2KHz. That's working correctly as shown by my scope. But according to the PLL VI, it is always 1 Hz!
Thanks,
ROB M.

[Travis W]

Rob,

Have you tried setting the function to "Square" for the LockInPLL.vi?

Thanks,
Travis


square.JPG:
Loading Image...

[Rob M.]

Update: I know I have the PLL VI working properly. An app eng was able to figure out that something happened to the PLL VI when the sample was backwards-converted to operate to Labview 7.0. He's not sure why this occurred, but it was remedied with a simple cut and paste of the PLL icon from the traditional DAQ lock-in amp block diagram or the Labview 8.0 block diagram into the Labview 7.0 block diagram. B/C the PLL VI is password protected, there's no way of telling what happened to the VI in order to figure why it conked out.
So, just be aware that if you see this behavior in the DAQmx lock-in amplifier start-up kit, it might be due to LV version conversion issues, and it is easily fixed by the cut and paste of the VI for some odd reason.
Thanks for the help
ROB M.