Comment 10 for bug 107208

Before touching /etc/udev/rules.d, only one USB Serial adapter would be assigned ttyUSB0. The others would not be mapped in.

After adding the udev rules below, they are now working as expected, but the computer required a power cycle or the USB Serial adapters required being unplugged and replugged back in before they would communicate with their serial devices.

The following was helpful.
http://www.reactivated.net/writing_udev_rules.html#udevinfo

Thank you for the help.

# /etc/udev/rules.d/50-local.rules

# /dev/ttyUSB0
SUBSYSTEMS=="usb", ATTRS{manufacturer}=="Generic", ATTRS{product}=="USB to Serial Converter", ATTRS{serial}=="OCBPJ9HM", KERNEL=="ttyUSB[0123]", SYMLINK+="powercom"

# /dev/ttyUSB1
SUBSYSTEMS=="usb", ATTRS{manufacturer}=="Generic", ATTRS{product}=="USB to Serial Converter", ATTRS{serial}=="OCBAKZ7N", KERNEL=="ttyUSB[0123]", SYMLINK+="smartups", MODE="0660", GROUP="nut"

# /dev/ttyUSB2
SUBSYSTEMS=="usb", ATTRS{manufacturer}=="Generic", ATTRS{product}=="USB to Serial converter", ATTRS{serial}=="OCBQH84W", KERNEL=="ttyUSB[0123]", SYMLINK+="usrobotics"