Getting error "VISA: (Hex 0xBFFF0011)" with a USB

[Throggdor]

I've poked around the website and found a lot of people have gotten this error code sadly none of the posts I read through helped, hopefully someone can help me.

I'm getting the error "VISA: (Hex 0xBFFF0011) Insufficient location information or the device or resource is not present in the system."

I'm using the "VISA Configure Serial Port VI" and "VISA Close Function" vi's stanadrd in labivew as well as several others to send and recieve information to make sure its calibrated properly, now most of the time their is no issue, but in about 10% of the cases I get the above error.

The USB port is shared between two devices, its only connected to each device for a short peirod of time when in use never both at the same time, otherwise it is comepletly disconnected and COM4 disappreas from the Device Manager (see "Device Manager with the USB attached").

A few things I've noticed.

• The only time the COM4 shows up in NI Max is when their is a failure (see "NI MAX COM4 Settings during error"), otherwise its not their when the test is running even with the USB is attached, all the settings displayed are correct.
• The error happens during the "VISA Configure Serial Port VI".
• After the error happens even if I connect the USB device to my computer manually, the connection does not show up in Device Manager.

Thanks for taking the time to read my post.

[RTSLVU]

The device manager shows an error 45 (device not connected) that pretty much points to a sketchy driver (contact Silicon Labs) or a physically bad connection, not a LabVIEW issue.

[Throggdor]

Oh sorry about that. When I took the screen shot of the device manager the testing had moved beyond the point where the USB was connected, so the connection was an open. Thats why you see that error. a faulty connection is the first thing I ruled out. I verified that the connections are made physically with a DMM.

Another little bit of info is, when the error manifests the only way to fix it is to restart the computer.

Just to be on the safe side though I am going to reach out to Silicon Labs to see if they have an updated verson of the driver.

[RTSLVU]

I know it's a stretch but I had a similar problem with some Prolific USB to serial adaptors year ago. It turned out the adaptors we were buying were counterfeit and the new Prolific drivers were detecting the counterfeit chips and silently disabling them. Causing the adaptors to just stop working. Rebooting would fix it for a while but eventually they would just stop working, it's something with checking with Silicon Labs to see it they are doing anything like that with their drivers too. In my case rolling back the driver to an older revision made it stop failing, but the real soultion was to throw out all the Prolific adaptors and buy only FTDI chipset based adaptors directly from FTDI, not some third party brand.

[Sam_Sharp]

Classic case of 'dodgy USB to serial adapter' from the looks of it. Some of them are notoriously unreliable. Try one based on a different chipset (e.g. FTDI).

[Throggdor]

I've contacted SiLabs, to see if we can find out if the chips are counterfeit, after that I'll check on FTDI and see whats up.

[ben64]

That might also be cause by the fact you are using the same USB port for different devices. MAX may be expecting the other device and hence the device or resource not present message. Are you changing the alias name in MAX?

Any message with the warning issued by MAX (the yellow triangle with exclamation point)?

Ben64

[_Xilinx_]

Silicon Labs support was a total letdown for me concering LV support...   Avoid them for use with LV.

[Throggdor]

Well I'm only using the USB port to do the same thing on both devices, and thats it. Both devices can never be connected at the same time, They are both opened and closed seperatly.

I have not inputed the USB into Max at all, as a matter of fact when the USB port is connected I don't think it shows up in Max at all. I'll double check this to confirm.

[ben64]

USB equipment are identified by their manufacturer id and serial number. Even if the equipments have the same part number they will have different serial number. When you use an UART VISA alias are related to the equipment not to the port.

Ben64