NVITE | installation guide
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RS485 multi-drop communication
Multi-drop communication requires an addressable communication protocol, such as OSDP.
Termination resistors (120
Ω
) are recommended to prevent unwanted signal reflections on long RS485 communication
lines. The resistors should be installed at both ends of the communication line. See Figure 4 below.
Figure 4: RS485 multi-drop communication
Notes
•
Use shielded twisted pair cable when extending the RS485 wiring beyond the standard 5 meter cable.
•
Maximum RS485 cable length 1200 meters (
6000 feet
).
•
The RS485 interface is disabled while the USB interface is in use.
HOST
A
B
120
Ω
120
Ω
NVITE
A
B
A B
NVITE
A B
NVITE
