INVT Goodrive350 Series Operation Manual page 328

Goodrive350 IP55 High-ingress Protection Series VFD
For example, if the master sends a request message to a slave for reading a group of function
code address data, the following code is generated:
In a normal response, the slave returns the same function code. In an exception response, the
slave returns the following code:
In addition to the modification of the code, the slave returns a byte of exception code that
describes the cause of the exception. After receiving the exception response, the typical
processing of the master is to send the request message again or modify the command based
on the fault information.
For example, to set the "Channel of running commands" (P00.01, the parameter address is
0001H) to 03 for the VFD whose address is 01H, the command is as follows:
01
VFD
address
However, the "Running command channel" ranges from 0 to 2. The value 3 is out of the setting
range. In this case, the VFD returns an error message response as shown in the following:
01
VFD
address
The exception response code 86H (generated based on the highest-order bit "1" of the write
command 06H) indicates that it is an exception response to the write command (06H). The
error code is 04H, which indicates "Operation failure".
9.4.7 Read/Write operation examples
For the formats of the read and write commands, see section 9.4.1 and 9.4.2.
9.4.7.1 Example of reading command 03H
Example 1: Read SW 1 of the VFD whose address is 01H. According to the table of other
Modbus function addresses in section 9.4.4.2 Addresses of other Modbus functions, the
parameter address of state word 1 of the VFD is 2100H.
The read command transmitted to the VFD is as follows:
01
VFD
address
0 0 0 0 0 0 1 1 (03H in the hexadecimal form)
1 0 0 0 0 0 1 1 (83H in the hexadecimal form)
06 00 01
Write Parameter
address
command
86
Exception
response code
03 21 00
Parameter
Read
address
command
00 03
Parameter
data
04 43 A3
Error code
00 01
Data quantity
-310-
Communication protocol
98 0B
CRC
CRC
8E 36
CRC