Connecting to multiple KVASER - Leaf Light HS at once....

[sammy346]

I am trying to connect 2 Kvaser (USB) dongles to my computer using LabVIEW simultaneously...

They are connected to the computer with a USB Hub but that shouldn't make any difference.

I have: CANKing CAN bus monitor program and the Kvaser SDK and their LabVIEW library also - all installed.

When I run CANKing, the program can detect both USB devices and also the 2 virtual channels - 4 in all.

When I call the CanGetNumberOfChannels.vi the value returned is 3 - but should be 4.

I am assuming that the CANKing program uses the same API calls.

Any ideas, why the second device is not recognised??

[Jeff.St]

Hi Sammy,

If you use the devices one at a time, does the CanGetNumberOfChannels.vi return the proper value?

Best,

[Michael_78 · Accepted solution]

I have seen this behaviour before, it is nearly impossible to cleanly unload the Kvaser dll when it is misbehaving.  Re-starting LabVIEW may help.  If the Kvaser hardware configuration tool shows 4 channels, then the CanGetNumberOfChannels dll call should reflect this.  It is not a good idea to add or remove a device with the driver loaded.

All the best,

Michael.

[sammy346]

Yes,

I was playing around with it further again yesterday and just calling a dll directly without using the VI (which is basically the same thing).

Results have been inconsistent although I was able to get the dll to recognise four channels at one point.

[TroyVia]

Just came across your question here.  An answer to your question is on our website at:

http://www.kvaser.com/en/support/faq/270-labview.html

As the FAQ at the link states, the problem arises due to when the DLL is unloaded.