END
5/14/2018
RTU Response Message of the Slave
T1-T2-T3-T4 (transmission time of 3.5 bytes)
START
ADDR
CMD
Write higher bits of the data address
Write lower bits of the data address
Higher bits of data content
Lower bits of data content
CRC CHK lower bit
CRC CHK higher bit
END
T1-T2-T3-T4 (transmission time of 3.5 bytes)
02H
06H
00H
08H
13H
88H
05H
6DH
T1-T2-T3-T4 (transmission time of 3.5 bytes)
ASCII Command Message of the Master
START
ADDR
CMD
Write higher bits of the data address
Write lower bits of the data address
Higher bits of data content
Lower bits of data content
LRC CHK Hi
LRC CHK Lo
END Lo
END Hi
‘:'
‘0'
‘2'
‘0'
‘6'
‘0'
‘0'
‘0'
‘8'
‘1'
‘3'
‘8'
‘8'
‘5'
‘5'
CR
LF
- 9 1-
START
ADDR Fuling Inve r te r Use r Ma nua l - slide pdf.c om
CMD
Write higher bits of the data address
Write lower bits of the data address
Higher bits of data content
Lower bits of data content
LRC CHK Hi
LRC CHK Lo
END Lo
END Hi
‘:'
‘0'
‘2'
‘0'
‘6'
‘0'
‘0'
‘0'
‘8'
‘1'
‘3'
‘8'
‘8'
‘5'
‘5'
CR
LF
6.3 Communication frame error check
Frame error check includes two parts: byte bit check (odd/even parity check) and entire frame data
check (CRC check).
6.3.1Byte bit check: The user can select d ifferent bit check modes according to the actual needs.
Alternatively, the user can select "no parity". T his will affect the check bit setting of each byte.
Even check: Insert a even check bit before data transmis sion to demonstrate the number of "1" in data
content is odd or even. If the number is even, check bit is set "0",otherwise the check bit is set "1", so the
parity remain unchanged.
Odd check: Insert a odd check bit before data transmission to demonstrat e the number of "1" in data
content is odd or even. If the number is o dd, check bit is set "0",otherwise the check bit is set "1", so the
parity remain unchanged.
For example, If we want to transmit "11001110", the number of "1" is 5, check bit is "1"when use even
check; check bit is "0" when use odd check. The receiver ne ed to do the parity checking. If the parity of
received data is not the same as the preset value,the communication has some errors.
-92-
http://slide pdf.c om/re a de r/full/fuling-inve r te r-use r-ma nua l
49/54
