After running program for a long time, it will skip every other measurment

[ANAD_PB]

After running the main program for a long time, it will still run without errors, but will only take everyother measurment. It will set up as thought it is going to work, but then no readings are recorded. Then the next measurement will work fine. Any advice?

[johnsold]

Please be more specific about your process. How does the program communicate with the measurement device? How fast is the sampling rate? How many samples do you acquire at a time? How many measurements or how much time elapses before the error begins? Is it always the same time or does it vary? Can you verify that the measurement device is actually making all the measurements?

Lynn

[ANAD_PB]

The measurments that I am taking are Composite Second Order Distortion (CSO) and Composite Triple Beat Distortion (CTB). I am using a RDL machine (multiple channel signal generator), connected to my DUT, which is read by a spectrum analyzer and then everything is connected to my computer, using GPIB cables. I'll run the test 5 or 6 times before the error occurs. Each test is about 30 different channel frequencies. It is hard to tell exactly when the error occurs, because each test is slightly different in length. When the error occurs the RDL will turn on the correct channel, but then immediately turn it off. It will not run a sweep with the SA. It is as though it completetly skips the testing and reading part in the code, which is written in between
the turning on and off of the appropriate channel. The sampling rate is about 10 seconds per channel.

[johnsold]

I have not done any GPIB work for several years, so I probably can't be of much more help. Does the RDL return any kind of error?

Lynn

[ANAD_PB]

No errors are reported at anytime during the testing.

When I close labview and re-open it, the problem is usaually fixed.

I am wondering if it could be the computer that I am running labview on. Maybe it doesn't have enough memory allocated to the program, but I don't know how to check for that or if it's even a possibility.

[JuanCarlos]

Hi,

With any GPIB application there are 2 places where errors can be generated: the instrument generates an error or the VI causes the problme. Make sure that you are reading the return value of the instruemnt and parsing it correctly for errors. Also make sure that you stop your loop if any of the VIs generate an error.

You could also chack if the data that you read is empty and set a breackpoint if there is no data coming in. That way you can single step and get more information on what is causing the error.

I hope this helps.

Regards,

Juan Calros