DRV-28 inverter
s Communication protocol
-272-
Code
Name
Definition
the register includes a value unexpected by the program.
04H
Operation
failure
The parameter is set to an invalid value in the write operation. For
example, a function input terminal cannot be set repeatedly.
05H
Password
error
The password entered in the password verification address is
different from that set in P03.00.
06H
Data frame
error
The length of the data frame transmitted by the upper computer is
incorrect, or in the RTU format, the value of the CRC check bit is
inconsistent with the CRC value calculated by the lower computer
07H
Parameter
read-only
The parameter to be modified in the write operation of the upper
computer is a read-only parameter.
08H
Parameter
cannot be
modified in
running
The parameter to be modified in the write operation of the upper
computer cannot be modified during the running of the inverter.
09H
Password
protection
A user password is set, and the upper computer does not provide
the password to unlock the system when performing a read or write
operation. The error of "system locked" is reported.
When returning a response, the device uses a function code domain and fault address to indicate
whether it is a normal response (no error) or exception response (some errors occur). In a normal
response, the device returns the corresponding function code and data address or sub-function code.
In an exception response, the device returns a code that is equal to a normal code, but the first bit is
logic 1.
For example, if the master device transmits a request message to a slave device for reading a group
of function code address data, the code is generated as follows:
0 0 0 0 0 0 1 1 (03H in the hexadecimal form)
For a normal response, the same code is returned.
For an exception response, the following code is returned:
1 0 0 0 0 0 1 1 (83H in the hexadecimal form)
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 device is to transmit the request message again or modify the command based on the fault
information.
For example, to set the "Running command channel" (P00.01, the parameter address is 0001H) of
the inverter whose address is 01H to 03, the command is as follows:
