Condair Amazon Echo, Instructions Manual

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8 Modbus interface
3.2 Network structure Modbus RTU
GND
D+ D–
GND
24 VDC
D+ D–
GND
D+ D–
24 VDC
X4 X4
SPA control board 1
(Server ID= 0)
Master
RS485
SPA control board 2
(Server ID= 1)
Shield
Fig. 1: Example Modbus RTU Network
All SPA control boards that are to be controlled must be connected to the master via the Modbus interface
according to the wiring diagram above.
– Connect the cable shield on one side with the functional earth
– Connect all GND together
– Install bus line separate from supply voltage
– Topology: Daisy chain
– All devices of the same network need the same settings concerning baud rate and parity
– Every Modbus device address can only be allocated once within the same network.
The Condair Omega or the Condair Delta SPA Control box always acts as a slave. In the master-slave
principle, only the master (e.g., control computer) can initiate data transmission. The affected slave
(Condair Omega or Condair Delta SPA Control box) responds to this and delivers the queried data to
the master or performs the action requested by the master.