Electrical installation
Instruction Manual FireGuard 2
13542E/5
31
5.6
Modbus RTU with repeater: Overview and installation
▪
To connect to the Modbus RTU with repeater, a Modbus module must be integrated in
the SIPORT 2.
▪
In the
Digi.interf.
\
General
menu, the
Module type
must be set to
Modbus
and the
Module location
to
SIPORT 2
.
▪
To be able to work with the Modbus, the bus parameters in the
Digi. interf. \ Modbus
menu must be correctly set. If the associated parameters are changed, the function
becomes effective only after a restart.
▪
If the photometer is used as a terminal device, DIL switch S2/1 must be switched ON on
the connection module (Figure 14, pos. 3).
▪
The addressing of the Modbus RTU interface is described in Section 8.7.
▪
Either a SICON M control unit or in-house control unit can be used as the Modbus mas-
ter.
▪
A twisted pair, shielded cable (SF/UTP) should be used. Characteristic impedance 120
±20 Ohm, capacitance < 60 pF/m.
▪
In order to prevent equalizing currents on the shielding, the shielding is grounded via a
capacitor on the insulated connection.
Figure 14: Overview of the Modbus RTU module in the SIPORT 2
Fieldbus interface (connection
print) for Modbus RTU with repea-
ter
Connector for SIPORT 2 print
DIL switch for matching resistors.
Switches (1 and 2) must be
ON
Modbus RTU terminals. Galvanically
isolated. (Cable cross-section: 0.08 ..
1.5 mm
2
)
Modbus RTU terminals. Con-
nected to ground potential. (Cable
cross-section: 0.08 .. 1.5 mm
2
)
