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
131
Serial Communications User Manual
(2) Function 06H
：
preset signal register
Presets a value into a single holding register (4 x reference). When broadcast, the function
presets the same register reference in all attached slaves. The maximum parameters
supported by various controller models are listed on page.
Ex. To inverter in F0H address protocol, pre set data 6000(1770H) into 0080H register,
the protocol frame will listed as below.
Query
Field Name
Example (hex)
ASCII code
RTU 8-Bit Field
Header
‘ : ’ (colon)
None
Slave Address
F0
F 0
1111 0110
Function
06
0 6
0000 0110
Register Address Hi
00
0 0
0000 0000
Register Address Lo
80
8 0
1000 0000
Preset Data Hi
17
1 7
0001 0111
Preset Data Lo
70
7 0
0777 0000
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 0110
Function
06
0 6
0000 0110
Register Address Hi
00
0 0
0000 0000
Register Address Lo
80
8 0
1000 0000
Preset Data Hi
17
1 7
0001 0111
Preset Data Lo
70
7 0
0777 0000
Error Check
LRC (2 chars)
CRC (16 bits)
Trailer
CR LF
None
Total Bytes
17
8
D. Error check Generation
(1) LRC Generation
Add all bytes in the message, excluding the starting colon and ending CRLF. Add
them into an eight-bit field, so that carries will be discarded.
Subtract the final field value from FF hex (all 1's), to produce the ones complement.
Add 1 to produce the two's-complement. Ex. The query data is F0H + 06H + 00H +
80H + 17H + 70H = FDH, the two’s complement is 03H. The ‘0’ & ‘3’ will be the
