DRV-28 inverter
s Communication protocol
-264-
MSB of CRC
9DH
END
T1-T2-T3-T4 (transmission time of 3.5 bytes)
The definition of the response information is described as follows:
The value of ADDR is 01H, indicating that the message is transmitted by the inverter whose address
is 01H. The ADDR information occupies one byte.
The value of CMD is 03H, indicating that the message is a response of the inverter to the 03H
command of 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
"LSB of CRC", 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, we
can see that 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 inverter. One command can be used to write
only one piece of data. It is used to modify the parameters and operation mode of the inverter.
For example, to write 5000 (1388H) to 0004H of the inverter whose address is 02H, the structure of
the frame is described in the following table.
RTU master command (transmitted by the master to the inverter)
START
T1-T2-T3-T4 (transmission time of 3.5 bytes)
ADDR
02H
CMD
06H
MSB of data writing address
00H
LSB of data writing address
04H
MSB of to-be-written data
13H
LSB of to-be-written data
88H
LSB of CRC
C5H
MSB of CRC
6EH
END
T1-T2-T3-T4 (transmission time of 3.5 bytes)
RTU slave response (transmitted by the inverter to the master)
START
T1-T2-T3-T4 (transmission time of 3.5 bytes)
ADDR
02H
CMD
06H
MSB of data writing address
00H
LSB of data writing address
04H
MSB of to-be-written data
13H
