Driver Filter

[zenthoef]

Does LabVIEW/MAX use some kind of "driver filter"?

I am troubleshooting a connectivity issue with a CP2102 (USB to serial convertor) when interfacing this hardware to LabVIEW. Sometimes LabVIEW VISA will loose connectivity with the CP2102. SiLabs (the chip manufacturer/designer) has asked me if there is a "filter driver" in LabVIEW that may be interfering with the driver associated with the CP2102. 

I doubt there is anything in LabVIEW, VISA, or MAX that would interfer with a 3rd party driver that implements a virtual com port, but I am not sure. Does anyone know if there is any sort of "driver filter" that may cause such a problem in LabVIEW, VISA, or MAX?

Thanks.

[Hueter]

If the CP2102 is emulating a COM port then from LABVIEW and MAX's perspective it should just look like a COM port. We do not use any driver filters. When you lose connection what do you have to do to reconnect?

[zenthoef]

Thanks for confirming what I suspected. The CP2102 does emulate a COM port, and in MAX it does look just like a COM port.

When the connection is lost it will generally give the error -1073807360 (misc system error), show up fine in device manager, and show up with the yellow/black exclamation mark in MAX. To restore the connection, I generally have to shut down the test fixture that uses the CP2102, unplug the USB connection, and restart the computer. Then, after the restart, I reconnect everything and it will generally come back up.

One thing that may have caused these problems is IT told me a couple days ago that computer had a virus on it that *may* have interfered with USB operations. So maybe that was the root of the problem the whole time... Since the virus was removed we haven't had this problem anymore, but it was a very intermittent problem that happened once every week or two. So I'll have to wait and see if the problem is resolved over time...