ibdev hang

[jack249]

If I did not connect the GPIB device to my PC (via USB), when my program execute function ibdev, the program will hang and I have to terminate it.
Based on the GPIB documentation, the function should return negative value. How to solve this problem?

[Curt_C]

Hi,

Are you sure the problem is ibdev? That function just creates a device descriptor to use in any calls made to the instrument. It returns the device descriptor or -1.

You should get an 'EBUS' error on any calls made after the ibdev function. 

"EBUS indicates that no devices were detected on the bus.  Verify that your instrument is powered on and properly connected to your GPIB interface."

Curt

[jack249]

I've put a breakpoint on this line:

dev=ibdev(gpib_boardindex,gpib_pad,0,T100ms,1,0);

whereby dev, gpib_boardindex and gpib_pad are int variables. In this case, gpib_boardindex and gpib_pad are 0. And I did not connect the USB to GPIB adapter to my PC. When I step over this line (F10), my debugger (Qt MinGW) will pop up error message of Segmentation Fault.

[Makoto]

You look like using GNU for Windows. How is the problem going when using NI's GPIB interactive app (IBIC) or when writing the same program with Microsoft C/C++? Also, what is your OS platform?

[jack249]

OS: WIN7 64 bit Home Basic

In Mircrosoft Visual Studio 2010, when I step over ibdev (USB to GPIB adapter not connected to my pc), this line occur in the output panel:

First-chance exception at 0x76f28dc9 in Read Write.exe: 0xC0000005: Access violation writing location 0x00000014.

[Curt_C]

Hi,

Try using the ibfind function before the ibdev and see what that returns

ibfind(GPIB0)

Curt