'DAQmxGetDevSerialNum' delivers a serial number even when board is disconnected ...

[JPR06304]

Hello,

I am a "newbie" with NIDAQmx and a former user of traditional NIDAQ 

library in C/C++. I use an "USB-6212' board. I am trying to migrate all

my NI applications from NIDAQ to NIDAQmx and it is a bit puzzling...

My question is the following:

the function 'error=DAQmxGetDevSerialNum( "Dev1", &SerialNumber )' delivers a valid

serial number (ex: 30974407) when my USB-6212 board is connected. BUT,

when I physically unplug the USB plug of my board, the same function still delivers

the SAME serial number (and not 0), and the return code 'error' is still 0 (success).

So, I cannot anymore use this function to verify that my board is actually connected

(as I used to do with traditional  NIDAQ).

More puzzling, the 'DAQmxGetDevIsSimulated( "Dev1", &Simulated )' sets the variable

'Simulated' to 0, whether my board is connected or not...

So, how can I assess programmatically the presence of the board ?

Thanks in advance for your help !

J.P. Rivet

[Kevin_Price]

The MAX database retains the association between the device serial # and its common name or alias (like 'Dev1').  This is meant as a feature, not a bug, so that the *same* name/alias can be associated with the device whenever it's present, no matter how many USB detachments and reattachments of various things have happened in the meantime.

The idea of a 'simulated' device is distinct from this.

In LabVIEW, I didn't quickly find a device-related property that looked like it would help me identify whether a USB device was physically attached or not.  You may need to try to create, maybe run, and then clear a simple task on the device.  You'll get an error if the USB device isn't attached.

-Kevin P

[JPR06304]

Hi Kevin,

Thank you for your quick answer !

Things are clearer now...

With my best regards

J.P.