NO.6 Detailed Function Description
70
Secondary reverse compensation of CDH is 34H, so transmitted data content is:
3AH 30H 31H 30H 32H 30H 33H 30H 33H 30H 42H 42H 38H 33H 34H 0DH 0AH
4. End bit
RTU mode ends in a manner of mute (>50ms) and ASCII ends in a manner of
CR(0DH)LF(0AH).
[Note] Data type in the communication: Transmitted data in the communication is
hexadecimal integer, for parameter value of function code, the minimum unit can be
determined according to scaling position of the parameter in function list; for instance,
the minimum unit of P003 is 0.01Hz. Thus, communications transmission 3000
represents 30.00Hz as per Modbus protocol.
(II) Function examples
1. 01 Read function code data
[Example] Read main frequency (function P003), parameter value is 30.00Hz (0B B8 in
hexadecimal system)
Communication code
Start
bit
Data format
Check
bit
End
ADDR
CMD
LEN
DATA
RTU
mode
Transmission
>50ms
01
01
01
03
11 89
>50ms
Reception
>50ms
01
01
03
03
0B
B8
CB 0C
>50ms
ASCII
mode
Transmission
3AH
30H
31H
30H
31H
30H
31H
30H
33H
46H
41H
0DH
0AH
Reception
3AH
30H
31H
30H
31H
30H
33H
30H
33H
30H
41H
41H
38H
33H
35H
0DH
0AH
2. 02 Alter function code
[Example] Alter parameter value of main frequency (function mode P003) into 30Hz (0B B8
in hexadecimal system)
Communication code
Start
bit
Data format
Check
bit
End
ADDR
CMD
LEN
DATA
RTU
mode
Transmission
>50ms
01
02
03
03
0B
B8
8F 0C
>50ms
Reception
>50ms
01
02
03
03
0B
B8
8F 0C
>50ms
ASCII
Transmission
3AH
30H
30H
30H
30H
33H
0DH