Goodrive350 IP55 High-ingress Protection Series VFD
Communication protocol
-284-
The Read/Write (R/W) characteristics indicate whether a function can be read and written. For
example, "Communication-based control command" can be written, and therefore the
command code 6H is used to control the VFD. The R characteristic indicates that a function
can only be read, and W indicates that a function can only be written.
Note:
Some parameters in the preceding table are valid only after they are enabled. Take the
running and stop operations as examples, you need to set "Running command channel"
(P00.01) to "Communication", and set "Communication running command channel" (P00.02)
to the Modbus/Modbus TCP communication channel. For another example, when modifying
"PID setting", you need to set "PID reference source" (P09.00) to Modbus communication.
The following table describes the encoding rules of device codes (corresponding to the
identification code 2103H of the VFD).
8 MSBs
Meaning
8 LSBs
Meaning
0x01
GD
0x08
GD35 vector VFD
0x09
GD35-H1 vector VFD
0x0a
GD300 vector VFD
0xa0
GD350 vector VFD
9.4.6 Fieldbus scale
In practical applications, communication data is represented in the hexadecimal form, but
hexadecimal values cannot represent decimals. For example, 50.12 Hz cannot be represented
in the hexadecimal form. In such cases, we can multiply 50.12 by 100 to obtain an integer
5012, and then 50.12 can be represented as 1394H (5012 in the decimal form) in the
hexadecimal form.
In the process of multiplying a non-integer by a multiple to obtain an integer, the multiple is
referred to as a fieldbus scale.
The fieldbus scale depends on the number of decimals in the value specified in "Description"
or "Default value". If there are
n
decimals in the value, the fieldbus scale m is the power n of 10.
Take the following table as an example, m is 10.
Function
code
Name
Description
Default value
Modify
P01.20
Wake-up-from-sle
ep delay
0.0
–3600.0s (valid when the ones
place of P01.19
is 2)
0.0s
○
P01.21
Restart after
power cut
0: Restart is disabled
1: Restart is enabled
0
○
The value specified in "Description" or "Default value" contains one decimal, so the fieldbus
scale is 10. If the value received by the upper computer is 50, the value of
"Wake-up-from-sleep delay" of the VFD is 5.0 (5.0=50/10).
To set the "Wake-up-from-sleep delay" to 5.0s through Modbus communication, you need first
to multiply 5.0 by 10 according to the scale to obtain an integer 50, that is, 32H in the
hexadecimal form, and then transmit the following write command:
