SnapAV WPS-ACC-PTZ-CTRL, Руководство пользователя

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RS-485 Bus
This section presents various technical details of the system.
RS-485 Bus
As required by the RS-485 standards, the RS-485 bus uses half-duplexed data
transmission cables with impedance of 120 Ω. The maximum load on the
bus is 32 devices, including the PTZ keyboard controller and any peripheral
equipment like DVRs.
Transmission Distance with 24 AWG Cable
The table below shows the maximum transmission distance allowed by the
RS-485 bus.
If your system uses thinner cables, or the PTZ cameras are installed in an
environment with strong electromagnetic interference, or you have lots of
equipment connected to the RS-485 bus, the maximum transmission distance
will be decreased.
Baud Maximum Distance
2400 bps 5900 feet
4800 bps 3900 feet
9600 bps 2600 feet
19200 bps 1950 feet