displaying data from 8594A spectrum analyser using HP-IB

[ms1]

Hi,

I am setting up automation for my HP 8594A spectrum analyser so that it conducts an EMC radiated emissions test through LabVIEW. What I am trying to acheive is obtain trace data from the analyser and replicate this on a waveform plot. I have currently achieved communication through a NI GPIB-USB adapter and MAX using address 18. I have also developed a rudimentary program that sends HPBASIC write and read commands as attached. I have been using the manual to obtain several instructions and it mentions using M-format to obtain display data. some of these commands seem redundant they are automatically configured through LabVIEW. From the manual it states the following:

10 INTEGER A(1:401)

30 OUTPUT 718;"IP;CF 300MZ;SP 20MZ;SNGLS;TS;"

40 OUTPUT 718;"TDF M; TRA?;"

50 ENTER 718;A(*)

60 PRINT A(*)

70 END

This it states will setup the frequency range, arrange in M format and store in the computer and then print.

I am receiving numerical data and storing it in an array but I am unclear on how to graph it as it appears from the display. I am using ver 6.1.

Thanks

[Dennis_Knutson]

First, you don't have an array. You just have a string. You can use the String to Byte Array function according to the driver that is here. I would suggest you download the driver (7.0) and attach it to a post asking for help in converting it to 6.1. Or, you could upgrade to a version of LabVIEW that is a bit more recent.

[ms1]

Sorry, I used the String to Byte Array function but did not save it in the posted version. An upgrade is quite costly and I don't think my employer would allow it but I guess there's no harm in asking. I downloaded the driver and am curious to its primary function. From what I've read, it seems that it is used to establish communication between the PC and spectrum analyser which I already have. Obviously I can't use the driver yet because of version incompatibility and you said that there is a way to convert it 6.1. How is this achieved?

[Dennis_Knutson]

Yes, the driver is used to establish communication between the pc and instrument but it's not at all obvious that is what you have. For one, the driver converts the binary trace data into floating point numbers. Your code did not do that nor did it display the data in a graph.

Someone with LabVIEW 7 (not me, unfortunately), can save the driver to version 6.1. Having the driver will probably save you some time.