HD-TVI Speed Dome DS-2AE7232TI-A User Manual
UM THD DS-2AE7232T-x 020519NA
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Problems in the Practical Application
Normally, users adopt a star-shape connection method in construction. Under this situation, the
terminal resistors must be connected between the two farthest devices (as Figure 4, 1# and 15#), but
this connection method does not satisfy the requirement of the RS-485 industry standard, because it
can lead to problems such as signal reflection and anti-jamming ability decline when the devices are
distant. At this time, the dome will be uncontrollable, or self-running, etc.
Figure 28, Star Shape Connection
For such cases, the best way to add a RS-485 distributor. This product can effectively change the star-
shape connection to one that satisfies the RS-485 industry standard requirement, in order to avoid these
problems and improve communication reliability. See Figure 5.
Figure 29, RS-485 Distributor