Goodrive350-19 series VFD Communication protocols
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MSB on the left and LSB on the right.
"Data count" indicates the count of data to be read (unit: word). "Start address" is "0004H" and "Data
count" is 0002H, indicating that data is to be read from the data addresses of 0004H and 0005H.
CRC check occupies two bytes, with the LSB on the left and MSB on the right.
RTU slave response (sent from the VFD to the master):
START
T1-T2-T3-T4 (time gap with a min. length of
3.5 bytes)
ADDR
01H
CMD
03H
Number of bytes
04H
MSB of data in 0004H
13H
LSB of data in 0004H
88H
MSB of data in 0005H
00H
LSB of data in 0005H
00H
CRC LSB
7EH
CRC MSB
9DH
END
T1-T2-T3-T4 (time gap with a min. length of 3.5
bytes)
The definition of the response information is described as follows:
"ADDR" is "01H", indicating that the message is sent from the VFD whose address is 01H. The ADDR
information occupies one byte.
"CMD" is "03H", indicating that the message is a VFD response to the 03H command from the master
for reading data. The CMD information occupies one byte.
"Number of bytes" indicates the number of bytes between a byte (not included) and the CRC byte (not
included). The value "04" indicates that there are four bytes of data between "Number of bytes" and
"CRC LSB", that is, "MSB of data in 0004H", "LSB of data in 0004H", "MSB of data in 0005H", and
"LSB of data in 0005H".
A piece of data is two bytes, with the MSB on the left and LSB on the right. From the response, the
data in 0004H is 1388H, and that in 0005H is 0000H.
CRC check occupies two bytes, with the LSB on the left and MSB on the right.
10.4.2 Command word 06H, writing a word
This command is used by the master to write data to the VFD. One command can be used to write
only one piece of data. It is used to modify the parameters and running mode of the VFD.
