Planet Technology 23x Indoor Speed Dome Camera CAM-ISD48 - Manual (Page 15)

standards, problems such as signal reflections, lower anti-interference performance
arise when the cables are long in the connection. The reliability of control signals
could be downgraded with the phenomena that the dome does not respond to or
just responds at intervals to the controller, or does continuous operation without
stop
In such circumstances the usage of RS-485 distributor is recommended. The
distributor can change the star configuration connection to the mode of connection
stipulated in the RS-485 standards. The new connection achieves reliable data
transmission.
RS-485 distributor
. .
User’s manual 15