Hi! I made a simple VI as in the picture attached. When I done with this, the first time I ran it, it took less than a second and then gave a number, I suppose it is a GUID, then the program ended. Then I clicked Run again, it took a rather long time, a few second and than the program was down! My questions are... 1. why would it be down in a second run?2. I displayed the GUID in the number indicator, but is it not big enough to store the whole GUID? If not big enough, what should I use? Raymond

vgbraymond wrote: I was really confused. Firstly.. A guid should have 16 byte but I can store up to 8 byte (64bit) in one element, so my GUID here should be incomplete... How should I deal with this? Secondly.. I got two elements at the first time, and then I tried to unplug my mouse and (I am using a notebook so I have my mouse pad) run this program again, I still got two elements in the array.. why would this happen? Raymond Firstly, you allocate an array of 16 int32, not 16 int8 (bytes), then you pass it to the Call Library Node to a parameter that has long long array type. long long however is 64 bits so LabVIEW converts your 16 int32 into 16 int64 to pass to the function. That function fills in 16 bytes and returns. I hope you can see why you get what you get. Secondly the GUID returned is simply a GUID that you can use to enumerate the HID devices in your system. It is NOT the device enumeration itself. For that you need to do a lot more work in terms of calling several more Windows APIs among which some like SetupDiGetClassDevs(), SetupDiEnumDeviceInterfaces(), SetupDiDestroyDeviceInfoList() and HID_FindDevice(). Message Edited by rolfk on 10-13-2009 08:24 AM

LabVIEW

Problem about GetHidGUID .... (Not Solved)

Solved!

First: Thank you all for sharing your information!

Without it I would have had more headaches with getting to work the setupapi functions in LabView. That's why I uploaded a lbb for debug and a working USB-Devices_SetupApi_Properties.vi (LabView2014). So others can have advantage of it and having less headaches for using setupapi in LabView.

Best regards...