is it possible for the test equip. to tell me the measured data is ready?

[Jessica]

When programming to read from a test equipment (e.g. ocsilloscope)
connected to PC/GPIB, many times I have to set a delay before reading
the value, otherwise the return value will be some invalid numbers
(e.g., 0). To achieve valid test results and testing time reduction, I
used trial-and-error to get a "minimum" delay time. But even this
delay time which works for one equipment may not work for another.
It's such a headache!!!

Is it possible to poll/inquire the status of the test equipment in the
program if the measured data is ready? If yes, how?

Thanks a lot for your answer!

[LesHammer]

That would depend upon the particular piece of test equipment. How are you talking to the instrument
(IVI, Plug&Play, SCPI commands through LabVIEW VISA calls)?

Look in whatever instrument documentation you have for status register information. You should be able to set it up so that a status bit gets set whenever there is data available. You can either SPOLL the status register and look at that bit, or if you feel lucky you can set it up for an interrupt.

Les.Hammer@CompleteTest.com

[Noel]

If you are programming using VISA, the following link takes you to some examples of waiting until the instrument has data available. The example link also includes other examples of synchronizing your application with your instrument.

Using Instrument Status Registers with Service Requests and Polling