04-17-2014 12:51 AM
Hello,
I am working on a LabVIEW VI that gets occassional hung up while trying to read the Lock-In Amplifier. When I go to the block diagram, I notice that it gets hung up at teh read/write sub VI. This happens when I use my Low Frequency Lock-In Amplifier. When I use my High Frequency Lock-In, it is inconsistent: I have an XY Graph in the diagram, and some times only 50 increments can be plotted. Other times more than 5000 are plotted. I have tried swapping out Lock-In Amps and GPIBs. It seems to be more frequency dependent than anything else. Any ideas or assistance would be greatly appreciated. I have the VI attached.
04-18-2014 11:27 AM
It would be useful to learn a little more about your setup.
1. What exact hardware are you using?
2. What is the desired behavior of this code?
3. Has this worked in the past? If so, what changes have been made?
Thanks!
04-18-2014 02:35 PM
Hello,
Thank you for the reply. I am using a basic Michelson Homodyne set up to measure vibrations of a piezoelectric sample utilizing the converse peizoelectric effect. I have attached a lab instruction that has my setup in there. The only difference is that instead of a lock-in amplifier using its internal signal, I am supplying an external voltage to the lock-in from a function generator where the signal is split and is supplied to piezoelectric sample as well. Thank you for your help.
04-21-2014 03:50 PM
I misplaced the reply and replied to myself. My attachment is in this thread
04-21-2014 03:50 PM
I replied to myself by mistake. I have an attachment and setup description in this thread
04-21-2014 03:51 PM
I replied to myself by mistake. I have an attachment and setup description in this thread
04-28-2014 05:12 PM
Hi,
You mentioned that this may be a frequency dependent problem. What is the frequency of the Lock-In Amplifier that works, and are you able to determine a cut off frequency that it no longer behaves in the desired way?
Thanks
04-28-2014 07:06 PM
Hi DollarBrill,
Thank you for the question. The frequency that works does not seem to be specific. For example, 180 kHz may work great one day, but only give me 40 increment points the next day. However, 190 kHz can give me over 1000 points on one day and none on the next. I will take a closer log and give a better detailed response to this question.
04-28-2014 07:09 PM
Hello DollarBrill,
Thank you for your response and question. It is not very consistent, but some frequencies do work better than others. I will give a more detailed response within the next day. I do not have access to that data where I am.
04-28-2014 07:09 PM
Hello DollarBrill,
Thank you for your response and question. It is not very consistent, but some frequencies do work better than others. I will give a more detailed response within the next day. I do not have access to that data where I am.