data acquisition from SR 530 lockin

[Agupta]

Hello,

I need to read the output of the sr530 vector lockin and store them in a file.

I was wondering if there is any driver which will let me read frequency, output amplitudes & relative phase between the input & output signal!

Any help will be much appreciated!

Thanks a lot,

Ashutosh.

[Matt_S.]

Hi Ashutosh,

You probably can if you have any means to communicate with that device. Can you connect via GPIB or serial or USB? If so, you can use VISA to talk to the device. Then you just need a command set of instructions from Vector and you should be able to retreive those values from that device. From there you can use any of the VISA example programs and do simple communication with your device.

I hope this helps,
Regards,
-Matt S.

[Agupta]

Thanks a lot for the help Matt.

I can connect the device via GPIB. Let me tell you a bit more about the problem. As of now I was using a single channel lockin, EG & G 5209, to read the data(so I am kindda familiar wtih data acquisition... not much though). And the only thing I was reading was the output amplitude of the lockin.

Now I have to use the vector lockin, SR 530, and I will need to read both the output amplitudes, the phase & the frequency (all four of them)at the same time. And I am looking for a driver which can do this, i.e. which can read all four data simultaneously & store the result in a *.txt or *.dat file.

Do we have something like that?

Thanks,

Ashutosh.

[Matt_S.]

Hi Agupta,

I think this is the instrument driver you're looking for.

http://sine.ni.com/apps/we/niid_web_display.download_page?p_id_guid=E3B19B3E959A659CE034080020E74861

Let me know if that doesn't help.

Regards,
Matt S.

[Agupta]

Thanks a lot Matt.

I got the file & changed it to read continuously!

The problem is, the delay between the consecutive readings (of the three parameters) is about 1.6seconds! Which is real slow for my purpose!

Do you think it is a problem with the apparatus or with the way I wrote the code?

I have experimented a lot with it... it seems more to be a problem with the reading three numbers from lockin, so the delay is tripled (from 500 ms to ~1.6second)! When I reduce the timeout setting, it reads faster but it reads only zeros (i.e. non-sense)!

Any help/ideas will be most appreciated!

Thanks,

Ashutosh.

[Albert.Geven]

Hi Agupta

This driver is a very old and too complex driver for only reading out.step 3 and 4 do the real work

try to write this in a separate vi.

succes

[Agupta]

Hey Albert,
Thanks for your help!
I discussed this problem with our professor too. And we came to the conclusion that one possible reason for the high delay between the consecutive readings can be - that we are working in versy small frequency range (10-100Hz) and the lockin needs to average over several cycles before it can throw a value out! The mannual also suggests the same on page 3-4, a very high data acquisition time (2-25 sec) in the low frequency range!
Please let me know what you think about it!
Thanks a lot for your time!
Best regards,
Ashutosh.