frequency sweep problems

[chaitu]

Hi

Iam presently working wih a project in labview7.0.I found your address through the net.I need to develop a VI to automate the frequency response using HP34401A multimeter and HP33120A function generator using GPIB interface.I developed the VI,but iam geting some problems when Iam testing it for simple low pass filter.The function generator is resetting to zero before it is incrementing to the new value.Then it is incrementing and again it resets to zero before it goes to the new value.I have given the intitial value,final value and the number of steps per decade on the front panel.Another problem is that Iam getting the cutoff frequency value to be 338 hz when iam calculating manually, but with this VI iam getting 100hz.Could you help me in getting out of this trouble.I will send you the VI with this mail.Kindly let me know if you need any other subvis for testing.Iam sending you the folder zipped.

[craigherdman]

Chaitu,

The HP34401A is a very common instrument and it has a LabVIEW Plug and Play driver available for download here:

http://sine.ni.com/apps/we/niid_web_display.download_page?p_id_guid=E3B19B3E9351659CE034080020E74861

A similar driver for your other instrument can be found here (HP33120A):

http://sine.ni.com/apps/we/niid_web_display.download_page?p_id_guid=E3B19B3E958C659CE034080020E74861

I found these instrument drivers by searching the Instrument Driver Network on NI.com. To use these VIs simply unzip the .zip files into folders of the same name within the instr.lib folder of LabVIEW. When you restart LabVIEW the VIs will become available for use on the Instrument I/O->Instrument Drivers palette. Hope that helps!

Craig H.
NI Applications Engineering