VI_ERROR_IO

[RahulD]

I am communicating with three devices: one a pressure controller, second an oven returning temperature and third an electronic board communicating through a modem which returns pressure and temperature values from a gauge setup. I am using TestStand 3.1 to run a sequence to measure data for different pressure and temperature using serial port. The first two devices are connected to a USB expansion module. The one I am using is Edgeport/4. My electronic board is at my COM1.

All the LabVIEW VIs that I am using in TestStand seem to run perfectly well individually and they also run well as a sequence. But there is a random hang up with the VI that get me data from my board. The error returned is -1073807298 VI_ERROR_IO. I have synchronised all VISA I/O and tried, but the problem does not seem to go. My

I am attaching NI Spy captured data for when my sequence is running well and when it gets hung.

Please help me out.

[craigherdman]

Rahul,

What version of NI-VISA are you using? I would recommend downloading and installing the latest version to see if the error still persists:

Current VISA Versions

The error conversion routines are occasionally reworked from older versions of VISA. Also does your VI run outside of TestStand without this error?

Craig H.

[RahulD]

Thanks for your reply. I am using VISA 3.2. I will update to the latest version and see if it works. And No it has the same problem even if I run it outside of TestStand. There is some problem reading the first byte of data, which governs the sequence of data that has to be read. I seem to override the problem by checking whether my correct byte has been read. Though in real time this will not be the case, i seem to have overcome the problem temporarily. But am still on lookout for a permanent solution where i dont have the cushion of checking if my first byte is read or not, as it is all synchronised with time. Will let you know if your solution worked. Thanks once again.