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GD350A series high-performance multifunction VFD
-287-
High-order bit of data in 0004H
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 low-order bit", that is, "High-order bit of data in 0004H", "Low-order bit of data in 0004H", "High-
order bit of data in 0005H", and "Low-order of data in 0005H".
A piece of data is two bytes, with the high-order bits on the left and low-order bit 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 low-order bit on the left and high-order bit on the right.
9.4.2 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. For example,
to write 5000 (1388H) to 0004H of the VFD whose address is 02H, the frame structures are described
in the following.
RTU master command (sent from the master to the VFD):
START
T1-T2-T3-T4 (time gap with a min. length of
3.5 bytes)
ADDR
02H
CMD
06H
High-order bit of data writing address
00H
Low-order bit of data writing address
04H
Data content high-order bit
13H
Data content low-order bit
88H
CRC low-order bit
C5H
CRC high-order bit
6EH
END
T1-T2-T3-T4 (time gap with a min. length of
3.5 bytes)
RTU slave response (sent from the VFD to the master):
START
T1-T2-T3-T4 (time gap with a min. length of