I am upgrading an old software package from VB6 to VB.NET. The old system uses the CWSerial object for serial communication and that system works just fine. In the new software, we have upgraded the VISA driver to use the VisaNS dll.
Using this dll, we get the same interface in the software (same properties and functions, etc.), but some of the devices have started giving parity errors and framing errors when trying to read. (eg. NationalInstruments.VisaNS.VisaException: A framing error occurred during transfer. VISA error code - (0xBFFF006B), ErrorSerialFraming).
The errors are intermittent, but the code is running on the same computer in both software versions.I assume that the actually data passing back and forth on the serial lines is no different (is this true), so is the VisaNS dll more sensitive for some reason?