I have an application running in LabView 2010. It has been running flawlessly for 3 years. It polls two devices via RS485 and RS232 then logs and displays the results. I recently moved the computer and it was working OK until 2 weeks ago. Now I get an error -1073807339 when attempting a serial write using a 4 port PCI-232 card.
1) Card is functioning properly
a) I can send commands though the "connect to instrument" option for the appropriate port listed in NI-DAQ and the instrument responds.
2) The cabling is fine - I can see the data transmission at the controller (as far down the cabling as possible) using an ocilloscope
3) RS-485 communications in the same code using a PCI-485/2 is still working
4) Error seems to be arrising from VISA assignment, but its odd since it has been fine until now.
5) I even get the error when I use a simple write command with no response expected.
6) The computer's new location has no internet. Its been offline for 6 months. Does this version need periodic contacts with NI to retain functionality?