DAQ from a Rohde & Swartz (handheld) spectrum analyzer using Labview

[Izum27]

I have a handheld spectrum analyzer and want to aquire alot of RF measurements from it and put it in an excel document. I decided to use Labview becuase I am using Labview for other parts of this project. I just wanted to know how I can integrate Labview with this spectrum analyzer. Sorry I am new at this so please can someone be as simple as possible.

-Izum27

[JLS]

Hello,

The first step is determining what interface you have to communicate with the analyzer. For example, does it have a serial port? If so, you can simply connect a serial cable to your analyzer and use NI-VISA commands to communicate with it. It is likely that the analyzer has some documentation detailing the peripheral interfaces it has, and the API (set of commands) that each interface understands. For example, you might write a string (using VISA Write) such as "data:10" and your instrument may respond with 10 data points (which you would retrieve with a VISA Read operation). The VISA palette (presuming you have installed NI-VISA, which would have been installed with the driver CD if you installed that after LabVIEW) can be found by right clicking in the block diagram and choosing (for LabVIEW 7.x where the express palettes are used by default) All Functions -> Instrument I/O -> VISA.

Repost if you have further questions. Including information such as the interface type, the syntax defining commands, and the form of the data returned (likely as a string, which you can parse - break apart - and convert parts to numeric form if necessar) will help me guide you more specifically to a solution in LabVIEW 🙂

Best Regards,

JLS

[Izum27]

I am communicating with the analyzer through the serial port of my computer. The analyzer has a optical to serial interface (9 pin). The product number is FSH-Z34 (RS-232-C cable). I looked through the data sheet and manual of the spectrum analyzer ( FSH3- Rohde&Swchwarz Spectrum Analyzer) and could not find out what syntax defining commands or the form of data returned. Do you know of anywhere I could find out this information? Also, when I have aquired the output of the spectrum analyzer how do I know extract from that output just the field strength or channel power from it?

Thank You for your help!

Andrew

[Izum27]

Sorry the optical interface is not 9 pin .... the serial port is the one that has the 9 pins.

[JLS]

Hello,

I tried googling relevant keywords but didn't find a document with that information. The only place to deterministically get that information would be the manufacturer of the instrument. They should be able to provide you with a list of commands and corresponding response formats. If you can get them to give you exmaples, that would be helpful as well. If you can at least get the commands, and successfully get a responses from the instrument, I can certainly help you programmatically parse the data, convert to numeric type, plot, etc. Also, of course ask any questions about how to use the VISA API to communicate with it. You'll generally be using VISA Open, Write, Read, and Close operations, and probably the VISA Configure Serial Port VI (use this right after the open function; it is just a VISA property node underneath, but use it especially if you care about termination characters, because it takes 2 properties to enable and disable this, and the VI does it correctly 🙂

Ok, best of luck with the manufacturer and I look forward to hearing back from you!

Thank you,

JLS

[Izum27]

Thank You I'll check that out ASAP.

[JLS]

Great! If you have any trouble using the commands, definitely repost! In the mean time, you could try standard commands such as (without quotes) "*idn?", "*rst", and "*tst?". Often you will need to append a termination character to these commands, for example, a linefeed or carriage return, or both.

I look forward to hearing back from you!

Thank you,

JLS

[Izum27]

Sorry that I took so long but I had to purchase a few things for this project. Like the remote control option for the FSH spectrum analyzer. Also I contact Rohde & Schwarz and the gave me the drivers for Labview to use along with the spectrum analyzer. I have attached the help file which I think explains all of the VIs that came in the library. From what I have seen it "seems" relatively simple to get whatever measurement I want but I need help with the VISA functions I think I have to use. I have also realized that I miss used the "DAQ". I will not be using a DAQ board at all. I will just be acquiring data. I'm sorry, I just found out that thats an actual term. I also attached another document (on the 1st page) which I think you need for the visa functions.

-Andrew

[JohnM 64]

Hi Izum,

I checked out the help file that you attached, and it looks like it is a very well organized instrument driver. There is even a Getting Started application that should be a good example of the overall flow that your program could take. The help on each function is also very well documented. Other than these functions, all you will need is the VISA Open and VISA Close functions at the beginning and end of your program. Good luck with your application!

john m
Applications Engineer

[Izum27]

Thats the problem I'm not sure how to use the VISA functions. Could you give me a quick overview of what the VISA open does how you initialize it and then what connects to the VISA close function? I've never used it before. Also if possible are there tutorials for teh VISA functions? Thank You.

-Andrew