User guide

18
Figure 7-2
7.4 RS485 Bus FAQ
Phenomenon Possible Reasons Solution
Speed dome
can run self-
diagnosis but I
can not control
it.
z Host address(baud rate) and
speed dome address(baud rate)
are not match;
z Positive and negative end of
RS485 Bus are misconnected;
z Connection cable is loose；
z RS485 Bus connection are cut
off;
z Modify host or speed dome setup ；
z Switch RS485 positive end and
negative end；
z Fix connection cable firmly；
z Replace RS485 Bus.
I can control
the speed
dome but is not
smooth
z RS485 Bus connection are not
good；
z One RS485 bus is off；
z The distance between host and
speed dome is too far；
z Parallel connected too much
speed domes.
z Connect RS 485 Bus again；
z Replace RS485 Bus；
z Add terminal matching resistance；
z Add RS485 distributor.