LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

myRIO USB file path

Solved!
Go to solution

I am creating data acquisition VI's for myRIO that save to a USB thumb drive connected directly to myRIO. However, for whatever strange reason sometimes myRIO changes the USB drive designation from say (U:/ to V:/) and recently from V:/ to W:/ . I am wondering what would cause myRIO to behave this way so I can avoid this happening in the future.

 

Thanks

0 Kudos
Message 1 of 5
(5,087 Views)

Greetings nfortier,

 

Windows is the one in charge of assigning the drive letter to any device that connects to the PC. The OS looks at the device ID and checks the registry and assigns the drive letter based on that, if there is no pre assigned letter it will assign the first unused drive letter. Take a look at this tread for more information and a method that can help you change the drive letter that's assigned to the drive.

 

Regards,

Alejandro C. | National Instruments
0 Kudos
Message 2 of 5
(5,055 Views)

I am aware of this. But specifically myRIO itself seems to re assigning the USB thumb drive. It is connected directly to myRIO via its USB port and thus I would think myRIO would be assigning that pathway. Unless I am misunderstanding something here. It only seems to happen when myRIO runs a VI that needs to save data to a USB thumb drive that it seems to change its default USB pathway. I am just wonder what this is because I have to change the pathway in the VI before I can collect data again.

Thanks,

N

0 Kudos
Message 3 of 5
(5,037 Views)
Solution
Accepted by nfortier

Assuming you are using the myRIO-1900 then yes, the one assigning drive letters is the myRIO and the way it performs this operation is the same described above (see manual, page 13).

 

The difference lies in the OS that is running on the device (RT Linux). The process that is mounting things automatically is pretty nested inside all of the other processes on the device.  It's called mdev. Looking on the system folders, check the following locations: /etc/mdev.conf (configuration file), plus, /etc/mdev/automount.sh and /etc/mdev/usb.sh (these files contain rules for mounting devices)

 

That being said, you can modify the contents of these files to force static drive letters. Unfortunately modifying the default behavior is something we cannot help you with (not recommended), but looking at the bright side, you can back up the files and play around with the options, plus, there is plenty of documentation out there to figure things out.

 

I hope this helps

Alejandro C. | National Instruments
Message 4 of 5
(5,027 Views)

Hello, have you solved your problem? Can you tell me how to solve it in detail?

0 Kudos
Message 5 of 5
(1,209 Views)