INVT Goodrive20-EU VFD Series, Руководство по эксплуатации

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Goodrive20-EU Series VFD Communication protocol
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}
In ladder logic, CKSM calculated the CRC value according to the frame with the table inquiry.
The method is advanced with easy program and quick calculation speed. But the ROM space
the program occupied is huge. So use it with caution according to the program required space.
7.2.3 ASCII mode
Name Definition
Coding
system
Communication protocol belongs to hexadecimal system. The meaning of message
character in ASCII: "0"…"9", "A"…"F", each hex is represented by the ASCII
message corresponds to the character.
Character '0' '1' '2' '3' '4' '5' '6' '7'
ASCII CODE 0x30 0x31 0x32 0x33 0x34 0x35 0x36 0x37
Character '8' '9' 'A' 'B' 'C' 'D' 'E' 'F'
ASCII CODE 0x38 0x39 0x41 0x42 0x43 0x44 0x45 0x46
Data
format
Starting bit, 7/8 data bit, check bit and stop bit. The data formats are listed as below:
11-bit character frame:
Starting
bit
BIT1 BIT2 BIT3 BIT4 BIT5 BIT6 BIT7 BIT8
Check
bit
Stop bit
10-bit character frame:
Starting
bit
BIT1 BIT2 BIT3 BIT4 BIT5 BIT6 BIT7
Check
bit
Stop bit
In ASCII mode, the frame header is ":" ("0*3A"), frame end is "CRLF" ("0*0D" "0*0A") by
default. In ASCII mode, all the data bytes, except for the frame header and frame end, are
transmitted in ASCII code mode, in which four high bit groups will be sent out first and then,
four low bit groups will be sent out. In ASCII mode, the data length is 8 bit. As for 'A'
–'F', its
capital letters is adopted for ASCII code. The data now adopts LRC checkout which covers
slave address to data information. The checksum equals to the complement of the character
sum of all the participated checkout data.
ASCII data frame format
Modbus message
Starting character:
“
0x3A
”
Slave
address
Function
code
Data
Checkout
Ending character:
“
0*0D
”“
0*0A
”
Standard structure of ASCII frame:
START ':' (0x3A)
Address Hi Communication address:
8-bit address is formed by the combination of two ASCII codes Address Lo
Function Hi Function code: