Comtrol RocketPort 550 uPCI Linux - Manual (Page 7)

7
There are two names for each port, one is for communication with a
modem, the other is for communication with a terminal or computer
Usually the modem connection has a Device name like 'cuaa..' and
the terminal/computer connection has a name such as 'ttyA..'
See section 6 for more information about port naming.
You are prompted to enter the Special Device name prefix for terminal ports:
Please enter the Special Device name for terminals [....]
… and for modem ports:
Please enter the Special Device name for modems [....]
Important Note:
You may be receive prompts for RS422 and RS485 ports. These are for
special OEM versions of the RocketPort 550 controllers and unless you are
using a specially supplied OEM version you should answer ‘n’.
This also applies if you are using RocketPort 550 controllers with
RocketPort interface box or Universal Interface box that support multiple
serial interface standards.
The installation script now copies the driver file into the module directory and
adds a command to initialisation scripts so that the driver is loaded whenever
Linux is rebooted.