Faq On Rs-485 Cable - Dahua SD22204DB-GC Installation Manual

3.3 FAQ on RS-485 Cable

Malfunction
The Device can perform self-
check, but is out of control.
The Device can be controlled,
but the operation is not
smooth.
Figure 3-2 Connecting method with RS-485 distributors
Possible Reason
Baud rate/address of the host
and Device are not matched.
Positive electrode and
negative electrode of RS-485
cable are misconnected.
Loose connection.
RS-485 cable is broken.
RS-485 cable is in poor
contact.
RS-485 cable is broken.
The distance between the
host and the Device is too
long.
Too many cameras are
connected parallelly.
11
Solution
Modify the baud rate/address
of the host or Device to be
matched.
Connect cables to the positive
electrode and negative
electrode correctly.
Connect the cables firmly.
Replace RS-485 cable.
Connect the RS-485 cable
firmly.
Replace RS-485 cable.
Install terminal resistance.
Install RS-485 distributors.