NI VISA

[Hasni]

Hi,

     Hope you will be fine. I am doing my final year project on Labview 2011. I have to read RF power from Agilent U2002A USB power sensor and plot it in labview. Instrument driver for Agilent U2002A power sensor is not available. so i am using Visa open, visa read, visa write, Visa close etc. to prgram my instrument. I have made a program but its not working it gives an error of timed out. I want you to plz make a program for me which only sends *IDN? command to the usb power sensor and returns the status of the device in the read buffer. I shall be very thankful to you. Plz also inform me that the instrument driver for that perticular USB power sensor or any alternate is available or not.

                                                                                            Waiting for your sympathetic consideration.

  Regards,

Husnain Taseer Student of BS(Electrical Engineering).

[ColdenR]

Hello Hasni,

I found an instrument driver for the Agilent U2002A:

http://sine.ni.com/apps/utf8/niid_web_display.model_page?p_model_id=17871

You will need to follow the installation instructions for Plug and Play instrument drivers:

http://www.ni.com/devzone/idnet/inetinst.htm

There are some examples in the zip file that should help you get started using the U2002A.

[Hasni]

Thanks for your reply. I have installed the driver and also tried to get measurements but it gives me an error. I connected the U2002A Power sensor with the computer, through the example (Aquire Measurement) given with the instrument driver the device replied for *IDN? command success fully but it generates an error in the block diagram at the output of the configure measurement.vi what should i do please help and tell me the steps which i should follow to measure power from the Power sensor successfully.  

[ColdenR]

Hasni,

What error message are you getting, and what inputs are you giving to the VIs?

And you should be able to use the VIs provided in the drivers to measure power. Follow the example VIs and adapt them to your application. Do you have any specific questions about how some of the VIs work?

[Hasni]

Firstly i connected the instrument with my computer then i installed the driver using "find instrument drivers" on labview. After that i opened "VISA driver wizard" and created a driver by giving PID (Product ID) and VID (Vendor ID) of the instrument after that i ran the example "U2000 series acquire measurement" on that it has given an error "VISA read error" ( tommorrow i will give you the error code and related information of the error after operating the instrument). Please tell me that the procedure which i have used is true or not and also make me sure that the given driver and the examples are properly designed and will work with the power sensor.

Regards,

Husnain Taseer

[ColdenR]

As long as you install the driver for the Agilent U2002A (linked above -- http://sine.ni.com/apps/utf8/niid_web_display.model_page?p_model_id=17871), then you should be good to go for talking to your U2002A. That driver has been tested for that sensor.

You can possibly find that same driver using the "find instrument drivers" method, but you want to make sure that it's the same driver as the one I linked to above. You don't need to use the "VISA Driver Wizard" though - you can just use the VIs that come with the driver you installed in order to talk to your instrument. Just make sure you follow all the documentation in the driver and correctly configure the serial port inputs (that is, if you plug into COM1 on your computer, be sure to use COM1 in the example).

[Hasni]

Actually the instrument which i am using is USB interface. if i don't creat driver from "VISA driver wizard" the name of my instrument doesn't appear in the "VISA resource name" therfore i m not able to talk with my instrument by just installing the driver.

[Hasni]

I am getting following error message...

Error -1074000000 occurred at Agilent U2000 Series.lvlib:Error Query.vi

Instrument reports:
-221,"Settings conflict"
-141,"Invalid character data"
+0,"No error"

Complete call chain:
     Agilent U2000 Series.lvlib:Error Query.vi
     Agilent U2000 Series.lvlib:Query Range Test.vi
     Agilent U2000 Series Range Test.vi

Please help me soon...

[ColdenR]

You're getting those errors because you're trying to create the driver using the VISA driver wizard, and you're not specifying all the details of the driver correctly. That's why it's easier to just use the driver which you can download from the website. Did you install the plug and play driver according to the plug and play driver installation instructions (http://www.ni.com/devzone/idnet/inetinst.htm)?

Also, what options do you see in the VISA resource name drop-down menu? Do you have NI-VISA and NI-Serial installed? If not, you can get them here:

http://www.ni.com/support/