C.TY TNHH TỰ ĐỘNG HÓA VIỆT TRUNG 02413.281.181-0989.984.666
Website:www.viet-trung.com.vn Đ/c:194-Nguyễn Trãi-Võ Cường-TP.Bắc Ninh
129
Serial
Communications
User
Ma
nual
C. Function code
This product support Function code 03H and 06H in MODBUS protocol.
(1) Function 03H：Read holding register
Read the binary contents of holding registers (4 x references) in the slave.
Broadcast is not supported. The maximum parameters supported by various
controller models are listed on page.
Ex: Read data from 3 continuous addresses in register. The beginning address is
0080H, the data frame are listed as follow.
Query
Field Name Example (hex) ASCII code RTU 8-Bit Field
Header ‘ : ’ (colon) None
Slave Address F0 F 0 1111 0110
Function 03 0 3 0000 0011
Start Address Hi 00 0 0 0000 0000
Start Address Lo 80 8 0 1000 0000
No. of Register Hi 00 0 0 0000 0000
No. of Register Lo 03 0 3 0000 0011
Error Check LRC (2 chars) CRC (16 bits)
Trailer CR LF None
Total Bytes 17 8
Response
Field Name Example (hex) ASCII code RTU 8-Bit Field
Header ‘ : ’ (colon) None
Slave Address F0 F 0 1111 0000
Function 03 0 3 0000 0011
Byte Count 06 0 6 0000 0110
1
st
Data Hi 03 0 3 0000 0011
1
st
Data Lo E8 E 8 1110 1000
2
nd
Data Hi 00 0 0 0000 0000
2
nd
Data Lo 07 0 7 0000 0111
3
rd
Data Hi 00 0 0 0000 0000
3
rd
Data Lo 00 0 0 0000 0000
Error Check LRC (2 chars) CRC (16 bits)
Trailer CR LF None
Total Bytes 23 11
To Next Page
Loading...