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7. CONTROL
7.1. COMMUNICATION PROTOCOL - MODBUS RTU
*Address of module 0x01
Operational parameters of communication line RS485 MODBUS (RTU):
9600Bd
1 start bit
8 data bits
1 bit even parity
1 stop bit
Each module must support even parity. If parity is not used, it is replaced by second stop bit.
Communication method:
Master – control system (BMS)
Slave – electronics Module D (Modbus module)
Only the control system can be connected.
After the first connection of power supply, the module is in the OFF state. The requested operational mode must be sent by the superior control system! After
the subsequent disconnection of the power supply, the module remembers its last operational mode.
Communication connector numbers:
A - 6
B - 7
GND - 8
MODBUS RTU:
In the RTU mode, every 8-bit byte of message contains two 4-bit hexadecimal characters. The transmission of a message must be continuous, the spaces
between the characters must not be longer than 1.5 character. The beginning and end of the message is identified according to the bus rest longer than 3.5
character. The RTU frame format is shown in the picture.
General structure of telegram [hex]:
Beginning
Address
Function
Data
CRC
End
> 3.5 characters
8 bits
8 bits
N * 8 bits
16 bits
> 3.5 characters
Data block length
Size of
ADU on RS-485 =
253 bytes PDU + address(1 byte) + CRC (2 bytes) =
256 bytes
Address
Master has not any specific address, only slave units have to have an address unique in all MODBUS site.
CRC
Field with generating polynom x16 + x15 + x2 + 1.
7.2. TABLE OF KEY CHARACTERS AND CONFIGURATION DATA
Factory Driver:
Intended for hardware setup (READ/WRITE)
Address
Name
Info
Min. Value
Max. Value
Default
Factory set register - without valid FactoryPass only read
10001
AC_Switch
0 - AC3
1 - AC5
0
1
0
10002
MaxFlowManual
% of fan power
70
100
100
10003
MinFlowManual
% of fan power
0
40
20
10004
Postheat_1
0 - none
1 - electric
2 - water
0
2
0
10005
MotorEC_set
0 - PWM
1 - analog (0-10V)
0
1
0
10006
TempEXT1
0 - non
1 - used
0
1
0
At the IC-ModBus regulator, it is necessary to always set AC5 on address 10001 (five-degree module)