3
Electrical connections EKWHCTRL1 with on-board Printed circuit board EKWHCTRL0
A
ModBus RTU Serial Connection
B
Serial connection for fancoil
+ A B -
A A B B -
A
B
For connection of the electronic board to a "Modicon Mod-
Bus" RTU serial communication network:
– connect to the terminal block on the wall control unit
For all other connections, refer to the diagrams and in-
structions in the installation manual.
The choice of materials and the routing of the connection
are fundamental for correct operation.
Use a bipolar shielded cable suitable for the RS485 serial
connection with a minimum section of 0,35 mm².
Keeping the bipolar cable separate from power supply
cables.
Chase out the wall in order to minimize the length of the
leads.
Complete the line with the 120 Ω resistance.
It is forbidden make "star" connections.
1.
Terminal block for device connection
2.
The terminal block for CP presence contact connection
3.
PCB
3
1
2
3
CP
+ A B -
A A B B -
N540022B
N540022B
L
N
Serial Port Features
Protocol
The serial communication protocol is “Modicon Modbus” in
RTU mode with the following settings:
• baudrate=9600
• data bits=8
• parità=nessuna
• stop bit=1
The implemented functions are:
• “03” and “06” respectively for the reading and writing of a
single register
• the main adjustment parameters (R/W), the acquired tem-
perature and the operating status are made available
