Experimental Physics and
Industrial Control System

"J. Lewis Muir" <[email protected]> · Thu, 18 Apr 2013 14:17:30 -0500

On 4/18/13 1:21 PM, Mark Rivers wrote:
> Thanks for all the replies I've received so far.  I am still reading and understanding them.
> 
> But now I have a more fundamental question, there is something I am not understanding about modprobe I think.
> 
> I now have 2 different USB ftdi_sio devices.  Both are manufactured by Newport but they are different models.
> 
> This is what lsusb shows for these devices:
> 
> Colorado:motor/iocBoot/iocWithAsyn>/usr/sbin/lsusb
> Bus 004 Device 007: ID 104d:3006 Newport Corporation
> Bus 002 Device 004: ID 104d:3000 Newport Corporation
> 
> Initially I plugged in the device with model=3006.  I then did modprobe to load the ftdi_sio driver for that vendor and model, and it created /dev/ttyUSB0.  It works fine, I can control it with no problems.
> 
> Now I plugged in the second device with model=3000, leaving the first device also plugged in.  The new device shows up with lsusb, as seen above.  However, it did not create a /dev/ttyUSBn for that device.
> 
> I then tried to run modprobe for the new device:
> 
>> sudo modprobe ftdi_sio vendor=0x104d product=0x3000
> 
> There is no error message.  However, it did not create a new /dev/ttyUSBn device:
> 
>> ls -l /dev/ttyUSB*
> crw-rw-rw- 1 root dialout 188, 0 Apr 18 13:10 /dev/ttyUSB0
> 
> There is still only device ttyUSB0, not a new ttyUSB1.
> 
> What am I doing wrong?

Hi, Mark.

With no /dev/ttyUSB* device files, what happens if the second device is
plugged in first?  Does it get assigned /dev/ttyUSB0?

Another thing to try would be to add the "debug" keyword to the end of
the modprobe command, and see if you get anything helpful in dmesg (or a
log file).

Lewis

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System