06-13-2014 02:51 PM
Hello World!
I have been experimenting with my myRIO unit and I have run into something strange in connection to USB devices
In my project I will be having multiple USB sensors attached to the unit for data collection
The system recognises the USB devices and communicates with them OK
It is if I unplug a sensor, all knowledge of the rest of the connected sensors is lost
for example if I have 3 USB sensors plugged in and I execute the shell command ls /dev/ttyUSB* I get the following
/dev/ttyUSB0 /dev/ttyUSB1 /dev/ttyUSB2
If I unplug one sensor and then execute the same command I get the following
ls: /dev/ttyUSB*: No such file or directory
If I unplug and replug in one of the remaining sensors the /dev/ttyUSB* records come back.
I have tracked this down to the /etc/mdev/usb.sh shell script that gets executed whenever there is an event on the USB bus
My shell skills are not up to snuff to be able to determine how to correct the issue, so I am asking the community if they have seen any similar things happening
Thanks for any help that anyone can give me
Dan