ACD320 user manual
Appendix
DATA（N-1）···DATA
（0）
Data of 2*N bytes: this part is the main content of
communications, and is also the data exchange core in
communications.
CRC CHK lower bit
CRC CHK higher bit
Detection value: CRC value (16BIT).
Frame tail END
T1-T2-T3-T4 (transmission time of 3.5 bytes)
In ASCII mode, frame header is ":" "0x3A" ,frame tail is "CRLF" "0x0D""0x0A").Except frame
header and frame tail, all other bytes are transmitted by ASCII coding system. It will transmit
high4 bits first, then transmit low 4 bits. The data length is 7 or 8 bit in ASCII mode. Capital
ASCII is used to demonstrate 'A'~'F' and use LRC check, cover the information from slave
address to data. The checksum is equal to the radix complement of the sum of all characters
involved in checking the data.
ASCII frame standard structure
START
‘:’（0x3A）
Address Hi
Address Lo
Communication address: 2 ASCII combine 8-bit address
Function Hi
Function code:
Function Lo
2ASCII combine 8-bit address
DATA（0）···DATA Data content:
（N-1）
nx8-bit 2nASCII combine data content
n<=16,maximum 32ASCII
LRC CHK Hi
LRC check:
LRC CHK Lo
2 ASCII combine 8-bit check code
END Hi
END Lo
End:END Hi=CR（0x0D），END Lo=LF（0x0A）
6. Command Codes and Communication Data
6.1Command Code: 03H (0000 0011), read N words (can ready a maximum of consecutive five
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    "