ALL-CAM2399-EP User Manual
© ALLNET GmbH Computersysteme 2015 – All rights reserved
Errors and omissions excepted
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situation, the terminal resistors must be connected between two farthest devices (as
Figure A-9, 1# and 15#), but this connection method is not satisfy the requirement of
the RS485 industry standard so that it will lead to some problems such as signal
reflection, anti-jamming ability decline when the devices are faraway. At this time, the
dome will be uncontrollable, or self-running, etc.
Figure A-9 Star Shape Connection
For such case, the best way is adding a RS485 distributor. This product can effectively
change the star-shape connection to which satisfies the requirement of RS485 industry
standard, in order to avoid those problems and improve the communication reliability.
Refer to the following figure.
Figure A-10 RS485 Distributor
Troubleshooting of RS485 communication
Problem
Possible Reasons
To Solve the Problem
The speed
dome
does the
self-test
action but
cannot be
1. The address or baudrate of
the speed dome does not
match with those of remote
control device.
1. Adjust the address and
baudrate of the remote
control device to match with
those of the speed dome.
2. The wire RS485+ connects
to the interface RS485- and
2. Connect the wire RS485+ to
the interface RS485+ and wire
