Appendix I RS485 Communication Protocol
118
code, but the first position is the logic 1.
For example: a message sent from one master device to one slave device is
required to read a set of inverter function code address data, it will produce the
following function code: 00000011 (hexadecimal 03H), for the normal response, the
slave device will respond the same function code. For the exception response, it
returns: 10000011 (hexadecimal 83H) . In addition to the modification to function code
for exception, the slave device will respond to a byte of exception code, which defines
the reason for exception occurrence.
When the application program of master device gets a exception response, the
typical handling process is to resend the message, or change corresponding fault
command.
MODBUS Exception Code Table
The password written into by the password authentication
address is different from the password set by user (y0.01) .
The request data address of host computer is disallowed;
particular, the combination of register address and number of
bytes transferred are invalid.
When the CRC check bit of RTU format or the LRC check bit
of ASCII format in the message sent from by host computer is
different from the value sent by auxiliary computer, the
authentication error message will be reported.
When the received function code from the host computer is a
disallowed operation; the slave in the wrong state may deal
with such requests too.
When the received data field includes in the disallowed
values. Note: it does not mean the register data item to be
stored includes an value unexpected by application.
Invalid
parameter
changes
In the write command parameter sent by the host computer, it
includes data outside the scope of the parameter or the current
state of write address is not available.
When the host computer performs read or write command, if
use has set password and unlocked the password, it will report
that the system is locked.
The inverter is busy (EPPROM is saving)
To Next Page
Loading...
Need help?
General
