[ale] /dev/ttyUSB0 question

[christopher at bergeron.com (Christopher Bergeron)]

Guys (and gal) - do any of you know how to make a USB device take the 
same place in the /dev tree when it's inserted?  Specifically, I have 
two USB -> serial adapters in my machine.  When it starts up, they seem 
to "swap" places randomly.

As an example, typically my machine will boot with
Device 1 assigned to /dev/ttyUSB0 and
Device 2 assigned to /dev/ttyUSB1

However, sporadically it will boot with:
Device 1 assigned to /dev/ttyUSB1 and
Device 2 assigned to /dev/ttyUSB0

I don't think the devices have changed which physical port they are 
plugged into.
I'm not sure what config file I should modify, or where to look for this 
issue.  It's affecting my apps that are looking for specific devices on 
specific file handles (/dev/ttyUSBx).

Can anyone shed any light on this for me?

Much thanks!
-CB