Trigger configuration using IVIScop driver

[UnaiDeusto]

Hi, I am running one application that works in the same way that the example "IviScope - Acq Dual Wfm Edge Triggered.vi" available in LabView. The problem appears when I set up a trigger level bigger than the signal amplitude.

For example, if I want to display a 10Vpp signal and the trigger level is 11V, the program and the scope (the real instrument) go down. In LabView, I receive the following error:  (Hex 0xBFFF0015) Timeout expired before operation completed.  And I have to reset the real instrument. 

In a hands on session, the trigger can be configurated bigger than the signal's amplitude, and nothing special happens: in this case, the dispayed signal is not updated because the amplitud is not bigger or equals to the trigger level. 

Any idea for a solution to this example and to make possible to set up a trigger level bigger than the signal amplitude? The goal is to emulate the same as in the hands on session.

Thanks,

[Dennis_Knutson]

You don't mention your scope but after the timeout, try doing an error query of the scope. Sometimes an instrument will stop responding until its error buffer is cleared. Or, you may simply need to clear the error and retry.

[UnaiDeusto]

The scope is the Agilent model DSO5012A and I only want to use IVI fuctions to control it.

Now, If i configure the trigger level bigger than the signal amplitude, the instrument's buttons don't work. I have to stop the scope and reconfigure it 

I am running an example from NI LabView.

[NathanT]

Hello Unai,

      Generally, if the level trigger is higher than the signal, the scope will not trigger acquisition, regardless of whether it was configured using an IVI driver or not.  The reason that the instrument's buttons did not work is probably because the instrument was in "Remote" mode.  There should be a button that you can push to put the instrument back into "Local" mode.  Please tell us more about your specific application needs.

Cheers,

NathanT

[Dennis_Knutson]

And did you try the IVI function I mentioned? You are going to have do do a little more programming than just run the example.

[UnaiDeusto]

Yes,  I try to read the error queue, but I think that that is not the problem

When the trigger level is configured bigger that the signal, the oscilloscope wait for a signal. So my problem is that the timeout expires because the scope is not able to read a signal. The scope goes into a state that can't be controlled in a remoted way.

I try to abort the signal adquisition (IVI Scope Aboret.vi), but I doesn't work due to the timeout. 

[NathanT]

Hello Unai,

    If you wait long enough, will the signal increase until it reaches and or exceeds the trigger level?  If so, you could just increase the timeout value.

It would be great if you could tell us more about your application and what objectives you want it to accomplish.

Cheers,

NathanT

[UnaiDeusto]

Hi,

I am to control the oscilloscope from a flash application. This application reproduces the oscilloscope and the user can perform the same tasks as in a hands-on session.

You can find and example of the application at weblab-visir.deusto.es/electronics   Here click at 'demo page', and then you can login as a guest. There is a user manual but it is only in spanish, sorry

Imagine the following scenario over the physical scope:

 1) The input signal is a 5V amplitude sine

 2) The trigger is 2 volts. Ok, the signal is displayed at the screen

 3) If you increase the trigger level until a value bigger than 5V, the signal is displayed but it is stopped. 

My problem is that if I perform the same steps in a remote way (with my application), in the 3th step, the scope waits for the signal (no signal is displayed at the screen). Then, as the application tries to read a signal from the scope (and it is not at the screen, because the scope can capture it trigeger level > amplitude)  the timeout is over and the scope waits for the signal indefinitely.

More or less, the problem can be reproduced with the attached file. Run it but without an input signal in the scope. When the scope tryes to read the record length appears the timeout. Ok it is logical response, but the scope doesn't response when I try to abort the adquisition....

[NathanT]

Hello Unai,

     Something that might help is configuring the trigger modifier:

 

If that does not help, please isolate the problem down to the minimum amount of code that reproduces the problem, take an NI-Spy capture of the problem occuring, and post both of them to this thread.  Please also let us know which instrument you are using and which exact instrument driver.

For in-depth troubleshooting steps, please see the Instrument Driver Troubleshooting Guide.

Thanks,

NathanT