KSB CalioTherm Pro 25 Installation & Operating Manual page 30

Connection to a building management system (BMS)
Address 1
Address n-1
Address n
Fig. 14: Modbus wiring for the pump sets
Table 10: Technical data of the Modbus interface
Parameter
Terminal cross-section
Interface
Bus connection
Cable length
Wave impedance
Data rates [baud]
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5 Installation at Site
Modbus master
Modbus
Modbus
Modbus
Connection to bus systems with Modbus
Description/value
2
1,5 mm
RS485 (TIA-485-A) optically isolated
2
0.5 mm , shielded twisted pair bus cable
▪ 1000 m max.
▪ Stub line impermissible
▪ For cable lengths > 30 m take suitable measures to ensure overvoltage
protection.
120 Ω (cable type B to TIA-485-A)
4800, 9600, 38,400, 57,600, 115,200
(19,200 = factory setting)
CalioTherm Pro
Wire the bus terminating
resistor to the master / enable
it
Modbus network cable with defined
wave impedance (e.g. Ethernet cable)
Vin
a1
0-10 V
0 V
R
a2
RUN
0 V
1
a3
2
D-
a4 D+
COM
0 V
L
a5 H
DUAL
0 V