how do i sort my *IBN? problem?

[fruitnveg]

Hi all,

I'm trying to get labview working with a MArconi 6200A scalar analyser, but the 6200A isnt receiving the *IBN? command correstly, saying its wrongly headed and wrongly terminated...but it knows its there, and it can be communicated but not used in a VI...any suggestions?

cheers

andy

[Dennis_Knutson]

The correct command should be *IDN? and not *IBN?. If you really are sending *IDN?, then you left how some important details. Like, what is the connection type? GPIB, Serial, USB, Ethernet? If the instrument responds to *IDN? with something other than a LabVIEW VI, what is the other environment you are using? What function are you using to send the command? Is it a VISA Write?

[fruitnveg]

yeh i meant IDN not IBN 🙂 well, im using GPIB, and the problem is with Measurement and Automation explorer. when you click "scan devices" on the gpib interface, it finds the instrument i want to use, but when it sends the *IDN? command as part of the scanning procedure, it fails, and unless this is done the I/O assistant cant be used in any VI created 😞

[Dennis_Knutson]

Okay, that's a lot different problem. You don't get a response from *IDN? in any environment. MAX is not LabVIEW.

The instrument probably doesn't support the *IDN? command. Older ones do not. Check your programming manual and see if *IDN? is even listed. Not supporting a *IDN? will not make any difference on whether or not you can use the Instrument I/O Assistant. As long as an instrument is listed in MAX, it will be listed as an available instrument with the assistant. You just have to send it the correct commands from the manual.

[fruitnveg]

yeh sorry i wrote the first one in a bit of a rush

The instrument does support the *IDN? command becuase its in the manual, but the one NI MAX sends it doesnt like, and it wont work with I/O assistant because unless MAX gets an answer, the device doesnt appear in the "select instrument" step of setting up I/O assistant.

It all seems to work fine when its plugged into say a marconi 6500 amplitude analyser, the *IDN? command works fine and that instrument about 15 years older than the 6200A i want LabVIEW to work with...

all help greatly appreciated

[Dennis_Knutson]

Does the instrument fail to show up in MAX or do you just get the message that *IDN? failed? If it's just the *IDN? failed message, are you able to send any other commands to the instrument? If you can't send any commands, it's possible that the instrument is expecting something else besides the EOI. You could try appending an \n or \r as termination characters. A termination character is also settable in the GPIB properties.

What version of NI-488 are you using and what type of GPIB controller is it?

[fruitnveg]

It shows up in max, it just states for identification that the *IDN? query failed, and I've tried all the option for termination characters, and im using NI-488.2 and using the PCMCIA GPIB as the controller

[Dennis_Knutson]

Well, you didn't answer the question about which version of NI-488.2 that you are using or whether any others commands work. Let's assume that you are using a recent version of the 488.2 driver.  Besides the termination settings, about the only other thing to change at the controller is the timing. Have you tried to send any other commands to the instrument in MAX or just the *IDN? If you have and they don't work, my first guess would be that there is something wrong with the instrument itself. You did say that a different instrument responds to *IDN? and that would indicate to me that the GPIB controller is okay. I would also assume that you used the same cable when you tested communication with the other instrument. Just to eliminate the GPIB controller as the problem, do you have a different one in another pc that you can use?