Frame START
ADR
ADR
01H
01H
03H
03H
FAH
33H
04H
00H
00H
00H
00H
F0H
02H
02H
56H
CBH
00H
CMD
CMD
Startup Add. high-order
Register Add. high-order
Register Add. high-order
Startup Add. low-order
Register Add. low-order
Register Add. low-order
Register number high-order
Register data high-order
Register number low-order
Register data low-order
CRC low-order
CRC low-order
CRC high-order
CRC high-order
ADR
ADR
CMD
CMD
Byte number
Register data high-order
Add. F002H
（
）
Register data high-order
Add. F003H
（
）
Register data high-order
Register data low-order
Add. F002H
（
）
Register data low-order
Add. F003H
（
）
Register data low-order
CRC low-order
CRC low-order
CRC high-order
CRC high-order
3.5-byte internal time
3.5-byte internal time
Slave ADR
add
1
247
： ～
CMD
08
complex command
refers to page 76
Supplement
：
（
：
）
03
read slave parameter
06
write slave parameter
：
；
：
DATA(N-1)
Data content
function code parameter address , function code
parameter number , function code parameter value
and so on .
：
Select check mode by the second part of FC.01
DATA(N-2)
DATA0
CRC low-order (accumulate sum high-order)
CRC high-order(accumulate sum low-order)
END
RTU frame format
：
CMD and DATA
CMD
03H
read N-word (at most 5-word)
：
，
eg:
read two value continuously.
The startup add F002 of the inverter, whose slave
address is 01, can
Host command frame
Host command frame
Slave responding frame
Slave responding frame
70
……
eg:
the 5000
1388H) in
the
（
Write
F00B Add of
inverter ,whose slave Add is 02H.
6DH
C6H
88H
13H
0BH
F0H
06H
02H
6DH
C6H
88H
13H
0BH
F0H
06H
02H
CMD
06H
write a word
：
，
And then a new message will startup after that time . The whole message frame must be transferred as a continuous
data stream. If there is pause time exceeds 1.5-byte internal time before the frame finished , the receive equipment will
refresh the non-integrated message and assume the next byte to be a address field of the new message. Similarly, a new
message starts with the former one in less than 3.5-byte internal time, the receive equipment will reckon it as the
continuation of the former, which will lead to errors because the value cannot be correct in the last checking field.
Chapter 7 EH600 Communication Protocol and Description of Communication
