RS-485 Cable 30
Appendix figure 2-1 Star type connection
We highly recommend RS-485 distributor which can avoid the problems and improve the signal
reliability by turning the connection to conform to RS-485 standard. See Appendix figure 2-2.
Appendix figure 2-2 RS-485 distributor adopted
Appendix 2.4 FAQ for RS-485
Problems
Possible reasons
Solutions
The speed
dome can
perform
self-check but
out of control.
Baud rate and address of the
host and speed dome are not
matched.
Modify the baud rate and address of the
host or speed dome.
Positive and negative polarities
of RS485 cable are
misconnected.
Switch the positive and negative
polarities of RS485 cable.
Connection cable is loose.
Connect the cables firmly.
RS-485 cable is cut off.
Replace the RS-485 cable.
You can
control the
speed dome
but it is not
smooth.
RS-485 cable is in poor
contact.
Connect the RS-485 cable firmly.
RS-485 cable is cut off.
Replace the RS-485 cable.
The distance between the host
and speed dome is too long.
Add terminal matched resistance.
Too many speed domes are
connected parallelly.
Add RS-485 distributor
