Bosch VG4-A-PSU0, Installation Manual

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32 en | Cable and Wire Standards AutoDome Power Supply Boxes
F.01U.250.895 | 1.0 | 2011.08 Installation Guide Bosch Security Systems, Inc.
3.4.3 Controlling the AutoDome via the RS485 Protocol
2-wire (shielded), half-duplex, differential, multi-drop (32
nodes), 4000 ft cable limit)
RS485 is capable of controlling a true multi-drop network and is
specified for up to 32 drivers and 32 receivers on a single 2-
wire bus. The AutoDome uses the 2-wire mode, although RS485
can be connected in a 2- or 4-wire mode.
The following figure illustrates the connections for RS485
connections.
NOTICE!
The wire shield must be tied to signal at both ends, if 2-wire
twisted pair is used. After connecting the wires for RS485
operation, make sure the slide switch on the main board to the
camera head is positioned toward the LEDs (default).
CAUTION!
Bosch recommends that multiple RS485 connections be
arranged as a connected series of point-to-point (multi-
dropped) nodes, as a line or as a bus. It is not recommended to
arrange RS485 connections as a star, ring, or as a multiple-
connected network. Star and ring topologies may cause signal
reflections or excessively low or high termination impedance.
Wire Type 2-wire shielded twisted pair
Distance 1219 m (4000 ft)
Maximum Baud Rate 57.6 kb
Gage 0.511 mm (24 AWG)
Wire Impedance 120 W
Slide Switch Toward LEDs (factory default)