26
en | Connector and wiring details
VARI-directional array
2018.06 | V1.3 |
Installation manual
Bosch Security Systems B.V.
5.5
RS-485 network in (8) and thru (9)
See also
–
RS-485 network, page 14
5.5.1
Network configuration
The RS‑485 network connection should be wired if the VARI is to be continuously monitored
during operation or to be used for commissioning a large system.
The RS‑485 interface permits multiple VARI line arrays to be “daisy‑chained” in parallel, so that
all units are controlled and monitored by the same PC. Two RS‑485 connectors (“in” and
“thru”) are provided on each VARI to permit such interconnections to be made easily. In such
a system, each VARI must have its own unique network address; this will be determined via
the VariControl software for each individual line array when the configuration file is loaded.
If only one VARI unit is to be connected to the RS‑485 network, the “thru” connector (9) can
be ignored.
The pinout of the two RS‑485 connectors is identical. They should be wired as shown in the
table and diagram below, using cable with two separate
twisted pairs
with
individual screens
.
Connector type: 5‑pole, 3.81
mm‑pitch:
RS-485 in
RS-485 thru
Pin
Function
Pin
Function
1
Ground
6
Ground
2
Data Tx+ (Y)
7
Data Tx+ (Y)
3
Data Tx- (Z)
8
Data Tx- (Z)
4
Data Rx- (B)
9
Data Rx- (B)
5
Data Rx+ (A)
10
Data Rx+ (A)
Because the VARI uses a full duplex RS485 interconnection, it requires a 5‑wire interface,
existing of a differential input port (AB), a differential output port (YZ) and a dedicated
network ground terminal (Ground), so the transmit (Tx) and receive (Rx) balanced data lines
must be wired via their own twisted pairs.
Ground
Ground
Ground
Ground
Figure
5.3: Structure of the RS‑485 network
A network is composed of one master device and one or more slave devices. A master device
can be a PC running the VariControl software and a USB to RS‑485 converter, part of the
VARI‑CS Configuration Set. All slave devices are wired in parallel, the master device is