i NEED HP4274a vi FOR CV CURVE

[mdwand]

I am using a HP4274A LCR meter to measure the capacitance vs. voltage profile of a liquid crystal.  I have Labview 5.1 on Win NT and need a vi to capture this data via HPIB.

Can anyone help me?

Thanks, Michael 

[Dennis_Knutson]

You are in luck. If you go to the Instrument Driver Network, you can do a search for '4274'. You will find a link to a third-party driver for it and it says it is written in version 5. 

It's really past time to upgrade though. You are extremely lucky to find something this old.

[mdwand]

Hi Dennis,

Thanks for the quick reply.  Yes, I found that vi before and it runs on my Labview 5 program.  Unfortunately, it will only plot Capacitance vs. Quality factor, dissipation factor, or ESR/G.  I need to scan Capacitance vs the AC voltage from 0 to 5 V at a fixed frequency of 1 KHz.

In regard to upgrade, I actually have version 6.1 but do not have the funds to upgrade anymore at this time.  Maybe if one of my proposals gets funded I can upgrade, but my requirements are very simple and I think the current software should do the job for this project.

How hard is it to modify the current vi so I can plot C vs V?  Michael

[Burban]

Michael,

You'll need to use the manual of the HP4227 to better understand the GPIB commands it supports.  As Dennis mentioned, you are very fortunate to find even this sample VI for LabVIEW 5.  I took a look at the VI, it looks like you will need to add the functionality to the HP4274A Single Measurement subVI where you will need to format some new GPIB commands based on the measurement.  That subVI focuses on both building the command string to send to the 4274 and decoding the string sent back.  If you understand the commands that your instrument supports, adding the functionality to this VI should not be overwhelming.