FOTEK GD20-004G-2, Operation Manual

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Goodrive20 Series VFD Communication protocol
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(excluding the byte). 04 means there are 4 byte of data from the "byte number" to "LSB of
CRC CHK", which are "MSB of data in 0004H", "LSB of data in 0004H", "MSB of data in
0005H" and "LSB of data in 0005H".
There are 2 bytes stored in one data with the fact that the MSB is in the front and the LSB is in
the behind of the message, the data of data address 0004H is 1388H, and the data of data
address 0005H is 0000H.
CRC occupies 2 bytes with the fact that the LSB is in the front and the MSB is in the behind.
7.3.1.2 Command code 06H (corresponding to binary 0000 0110), write a word
The command means that the master write data to the VFD and one command can write one
data other than multiple dates. The effect is to change the working mode of the VFD.
For example, write 5000 (1388H) to 0004H from the VFD with the address of 02H, the frame
structure is as follows.
RTU master command (sent from the
master to the VFD)
RTU slave response (sent from the VFD to
the master)
START T1-T2-T3-T4 START T1-T2-T3-T4
ADDR 02H ADDR 02H
CMD 06H CMD 06H
MSB of data writing
address
00H
MSB of data writing
address
00H
LSB of data writing
address
04H
LSB of data writing
address
04H
MSB of to-be-written
data
13H
MSB of to-be-written
data
13H
LSB of to-be-written
data
88H
LSB of to-be-written
data
88H
LSB of CRC CHK C5H LSB of CRC CHK C5H
MSB of CRC CHK 6EH MSB of CRC CHK 6EH
END T1-T2-T3-T4 END T1-T2-T3-T4
Note: Sections 7.3.1.1 and 7.3.1.2 mainly describe the command format.
7.3.1.3 Command code 08H, diagnosis
Sub-function code description:
Sub-function code Description
0000 Return data based on query requests
For example, to query about the circuit detection information about the VFD whose address is
01H, the query and return strings are the same, and the formats are described in the following
tables.