Realtime Waveform Acquisition LeCroy wavesurfer 44xs

[aelray]

Hello,

im pretty new to LV and my task is to write a program for a LeCroy Waversurfer 44Xs. The Program should acquire the data measured by the scope in relatime (if this is possible). When the signal acquired reaches a certain level (trigger) the program should save the acquired data to a file including some pre-samples.

My problem by now is that the example VIs included with the drivers from LeCroy only allow acquisition of a short period. i.e. the VI waits for the scope to measure data and thus returns a waveform of certain length.

Is it somehow possible to create a program as described above?

hope somebody can help me

[xdaf]

Which maximum delay will you accept from the triggering event to the complete WF acquisition by PC? Is it ok to wait for the complete WF to be acquired (and displayed) by your scope, and the transferred to your PC?

[aelray]

it's supposed to be a long time continous measurement, where only the data of the event (including some presamples) are of interest. most of the time the scope/the VI should only monitor the signal.

[xdaf]

If you don't need to display the traces until triggering event happens, you may set trigger mode to "single", create a loop that continously reads trigger mode, and acquire the waveform as the result becomes "stop". Remember to reset trigger mode to "single" after storing waveform.

[alanjb]

Hi aelray,

Alan from LeCroy Tech Support here... 

Please describe further what you mean by "long time continuous". What's your application?  How often are you needing to readout data, and with what sample rate requirement?

Best Regards,

Alan

[aelray]

hi alan,

it should monitor the signal for like an hour. The only data relevant is when it reaches the trigger level including some presamples and a sample rate of 1 ks/s should be absolutely sufficent.

[Dennis_Knutson]

Typically, all you would do is set the trigger condition on the scope and then just monitor the scope to see if it's been triggered. You can usually set the scope to generate an interupt when it's been triggered. There is no need to transfer any data to the pc until it has been triggered. While if varies by scope and I have not used this model, it's somewhat unusual to be able to continuously transfer data and really no need to generate so much bus traffic anyway.

[aelray]

can i confgure the scope to do that through a labview program? If yes, is there an example how it is done?

[Dennis_Knutson]

There's an example that uses an edge triggered acquisition and waits. You set the timeout in msec and every msec, an INR? command is issued to see if the scope has triggered. The example is with the rest of them in the driver.

Message Edited by Dennis Knutson on 12-21-2009 01:19 PM

[alanjb]

Hi aelray,

Alan from LeCroy Tech Support here...  i agree with Dennis 100% - see the examples that are included with the driver.  Feel free to modify them to create simple examples for your specific application (but save the modified versions with a new name.)  Let me point out a subVI that you'll want to use:  "Configure Sample Mode", which is in the "Configure" subpalette of the driver.  This would be used to put the scope into Roll mode, which is what you'll want to since you have a very long acquisition. 

Best Regards,

Alan