Hello! I use LabView to read data from oscilloscope (Tektronix TDS3000) through GPIB. Sometimes an error pop ups saying computer cannot establish connection because the device is locked (see screenshot below), it happens when the vi trying to check (sends a command through VISA write and read session) the device status (does it capture data first and is it ready to send the data or not). That error message happens once a while and without any correlation, so it is hard to diagnose it. I attached main sub VI (Single sequence acquisition V2.vi) where the error occurs and some sub vis that are needed to open it. Will appreciate any recommendations!
Are you performing any other operations on the scope in parallel? Where do you open the VISA session, it is not shown in the VI you posted.
EDIT: One tought, you are setting a timeout for the acquisition but you are not setting the VISA timeout. If VISA timed out it can cause the error you are seeing. I think the default VISA timeout value is 10 sec. To set it to a different value use the VISA Set Timeout property node from the VISA Advanced VIs and Functions palette right after you open the VISA session.
Hi ben64! Thanks for your feedback.
The scope is used only to read data (after all parameters are set). I believe one of the device own sub VIs has Visa Open command.
I aim to try your suggestion concerning time out issue. Right now, i tried another scope, and this error has not showed up so far. maybe it is just a concidence or the problem might exsist before due to a hardware defect.