INVT Goodrive350 Series Operation Manual page 319

Goodrive350 IP55 High-ingress Protection Series VFD
Number of bytes
MSB of data in 0004H
LSB of data in 0004H
MSB of data in 0005H
LSB of data in 0005H
CRC LSB
CRC MSB
The definition of the response information is described as follows:
"ADDR" is "01H", indicating that the command is sent from the VFD whose address is 01H.
"ADDR" occupies one byte.
"CMD" is "03H", indicating that the message is a VFD response to the 03H command from the
master for reading data. "CMD" 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 contains 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.
9.4.2 Command code 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.
For example, to write 5000 (1388H) to 0004H of the VFD whose address is 02H, the frame
structure is as follows.
RTU master command (from the master to the VFD)
MSB of data writing address
LSB of data writing address
MSB of data content
LSB of data content
CMD
END
START
ADDR
CMD
CRC LSB
CRC MSB
T1-T2-T3-T4 (transmission time of 3.5 bytes)
T1-T2-T3-T4 (transmission time of 3.5 bytes)
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Communication protocol
03H
04H
13H
88H
00H
00H
7EH
9DH
02H
06H
00H
04H
13H
88H
C5H
6EH