problems acquiring data from signal generator

[235689]

Hi, Im using the agilent 8648B signal generator and I want to acquire the signal data from the signal generator and display on the LabVIEW front panel waveform graph. I have confirmed that I could communicate to the signal generator as it responds to the command *IDN? . I have also tried using the ibrd command but it seems that I do not know how to use it, the signal generator display -420 query unterminated or RMT TLK and etc...

I have also tried this command SENS:DATA? which is to return waveform data from instrument, and it says TIMEOUT expired before operation completed. I have changed the timeout value on the pop up window when i pull out the intrument I/O asst function from the LabVIEW but it doesn't help and my device once again display the -420 query unterminated.

I have found a user manual and try reading it but I couldn't find the definitions for RMT TLK and etc...

May I know what is the command for acquiring the data from the signal generator and display using LabVIEW?

I really need help. Thanks!!!

[Dennis_Knutson]

There are drivers for the instrument available. Choose the one you want at http://sine.ni.com/apps/utf8/niid_web_display.model_page?p_model_id=533.

What I don't understand though, is what you are trying to accomplish. The instrument is a waveform source and the command SENS:DATA? is not something I could find in the manual. If you found it, what page is it on? The command is found in instruments that perform a measurement typically but not often on sources. If the command is not supported, then you would need another instrument (i.e. a scope) connected to the output to look at the waveform. What is the 8648 normally connected to and why do you need to capture the signal?

[235689]

Hi, thanks for your response.

Hmm... I need to display the waveform generated by the signal generator on LabVIEW waveform graph.

I have connected a scope to the signal generator to observe the signal.

I have already connected the signal generator and my computer using the GPIB USB cable.

If I want to acquire the signal from the signal generator and display it on LabVIEW, i need to pull out the function call the Instrument I/O asst right?

But what command I have to use in order to acquire the signal and display it? 

(I have try the *IDN? command to see if I could communicate with the signal generator and it works.)

[Dennis_Knutson]

Well, in order to acquire the signal and display it in LabVIEW, you need to query the scope that you have connected to it. My reading of the manual for the signal generator did not reveal any command to read the entire waveform from it. There's certainly no such command in it's driver.

[235689]

oh okie... thnks lotz for your help

[235689]

Hi

Currently, I would like to display the waveform generated by the Agilent E4438C signal generator on LabVIEW front panel, is there any command for displaying the waveform?

Although I could not display the waveform, but I managed to see the amplitude, frequency and the modulation index on the window where i type in my commands when I click on the instrument I/O asst function. However, when I connect the output nodes (amplitude, frequency and modulation index) to the indicator and run the VI, it prompt an error which says : VISA:  (Hex 0xBFFF0015) Timeout expired before operation completed, and I do not know what the error is.

Hope you could suggest a solution to solve this error. Thank You.

[A_Ryan]

Hello 235689,

I have a couple of questions for you:

1.  If National Instruments already has an instrument driver provided, why are you using the Instrument IO assistant instead?

2.  Are you using the correct termination character?

3.  Can you attach a screenshot of the LabVIEW code?

4.  Are you communicating with the correct instrument (correct device name)?

5.  Are you using Auto parse?

On a side note, depending upon the amount of data that you are trying to write this could also be a source of the timeout error.

Here is some additional information related to this issue:

How to acquire signal data from the Agilent E4438C Function Generator to the LV8.0?

agilent E4440A spectrum analyzer timeout error

[Dennis_Knutson]

If there is a command to read the generated waveform, it will be listed in the manual. If you have found such a command, could you provide a link to the manual and a reference to the page in the manual that the command is on?

I also question why you are using the Instrument I/O Assistant. If you really want some help with that, you will need to at least provide the commands you are sending and attaching the actual VI would be a bigger help. Your statement is a bit confusing because the frequency, amplitude, mod index are inputs you would normally write to the instrument.

[235689]

Thanks lotz for your help, im very new to LabVIEW. Actually i didn't know what the drivers could do, although i downloaded it but i didn't install it, thanks very much. I have already installed it and try using it.

Actually im doing my final year project and im doing am modulation, my main objective is to display the waveform generated by the signal generator.

Before that, i didn't know the signal generator could be configured using the LabVIEW instr drivers, so i actually set all the configurations of the signal generator manually and see if i could get the waveform and get it display in LabVIEW front panel. Now, i have set all the configs through LabVIEW instr drivers.

There is this function inside the instr drivers utility called the hpesgd Display.vi, may i know what is the function of it? Couldn't i display the waveform using that vi? Or there isn't any way that i could display the waveform?

I will attach my vi...

Very much appreciated

[Dennis_Knutson]

One thing you need to learn is how to use the built-in help. Go to the LabVIEW help menu and select 'Show Context Help'. Then you can move your mouse over the function and get a description of what it does. The help says 'This VI is used to set the controls and parameters associated with the signal source's LCD display'. Front a front panel, you can also move the mouse over controls and indicators and get a description of each of them. You can also look at the block diagram of any VI and see what commands are being used. You should then be able to look up those commands in the programming manual.

I think you need to take a step back and read the instrument manual. It almost sounds as if you are sending random commands to the instrument in the hope that something will work. If there is a command listed in the manual that will in some manner echo back the output waveform, I could not find it in my brief review of it (just like the previous instrument). A thorough review by you may turn up something and maybe someone who is more familiar with it can help. You should also try Agilent technical support.

I've used a lot of signal generators over the years and I can't remember offhand any that had a command that allowed you to query the signal output. There may be some with that capability but I've always used an instrument like a scope to see the actual output. To retrieve a signal from a scope would be simple (especially if you used a scope with a LabVIEW driver).

Lastly, for help with instrument drivers, go to http://www.ni.com/devzone/idnet/ and check out the links below on what a driver is and how to use one.