The Adder CATX-USBA is a USB Computer Access Module (CAM) with audio support
which connects to the keyboard, video and mouse ports of the computer and converts
these signals to be sent over UTP cable and onto the AdderLink CATx switch.
Increasingly important is the support of DDC (Display Data Channel) which allows
the communication of a computers video card and the screen. Unless this communication
is actively supported, as all Adder CAMs do, then the desired resolution may not
be displayed and in some cases nothing will be displayed at all.
Where computers only present USB keyboard and mouse it is important to ensure that
all USB functions are supported. These include ‘keep alive’ circuitry. It is common
during periods of inactivity that a computer will occasionally send a ‘keep alive’
signal to it’s keyboard and mouse, unless this is responded to the computer may
stop and keyboard and mouse communication. Sun computers will request a ‘country
code’ from the keyboard and unless this is actively supported some Sun computers
may not work.
