n9020a VXA using gpibWrite() / gpibQuerry()

[ronnyyong]

I try to read back an EVM result from N9020A, but having problem to use gpibWrite() or gpibQuerry() function with VC++. The SCPI command I trying to send is < :CALC:W11A:DATA4:TABL? "EVM\" >. I suspect the error is coming from the " " appeal within the SCPI command itself.

Can anyone help here?

I adding test feature with N9020A into existing program code.

[chris_amadasun]

Hello,
I looked at the programmer reference manual for your device here, I could not find the EVM command.
At this point I do not believe that your 9020A supports that particular device.

There should be a command in the programmers reference that will perform the task you require.

[ronnyyong]

Thanks, christian.

This command is from 89601-90001, new release f/w of N9020A.

I had try some which I search from web on VC++ tip,  eg like \", or \x43, try to force VC compiler that this " is a special string I want to send, but still can't get it work.

could it be the gpibWrite() / gpibQuerry() cannot recognize those special string?

Do you have any workarround trick for for, "EVM\" ?

Thanks in advance.

[chris_amadasun]

Hello I am assuming that you are using the quotation marks "" in the command string you are sending?
Have you tried send the command without the quotation marks i.e just EVM\  

Let us know if this helps.

[ronnyyong]

hi Christian,

I had try it w/o "", MXA will have error.

The SCPI command send down must inlcude "EVM\".

I try using NI MAX with the VISA Interactive control, basic I/O write, I type in <:CALC:W11A ATA4:TABL? "EVM\">, there is no problem or sending, instrument don't show error of receiving, and I can read back the result by using basic I/O read.

Thanks.

[jjp377]

Did you try "\"EVM\""

[kamal_k]

i use the following scpi commands on the N9020A Spectrum Analyzer to read my EVM qpsk values:

inst wcdma

freq:cent 300 MHz

conf:evmq

fetc:evmq?

and it outputs all the evm qpsk values

[markus kossmann]

Did you allready run NI Spy ?  If the command string gets mangled you should see it there how it is mangled .  Probably you have to quote not only the quotes but also the backslash.  Something like this : \"EVM\\\"