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PV500-67 03/17
3.6 EXCEPTION RESPONSE:
Exceptions result from a valid packet being received by the Slave device but the slave is unable to complete the
command. This can be the result of an invalid address, or a write command to a read only Register. Table 1 provides
an explanation of each Exception Code and the possible cause.
Table 1
EXCEPTION CODES:
Exception
Code
Name
Meaning
01
Illegal Function
The function code received in the query is not an
allowable action for the slave. Only function codes
0x03, 0x06, 0x10 are valid commands.
02
Illegal Data Address
The data address received in the query is not an
allowable address for the slave. More specifically,
the combination of reference number and transfer
length is invalid.
03
Illegal Data Value
Requesting a register that does not exist. More
than 5 elements requested. Writing a parameter
out of range. Writing to read only register.
04
Slave Device Failure
An unrecoverable error occurred while the slave
was attempting to perform the requested action.
The device didn’t succeed in reading or writing
requested operation. Operation (Ram, E2, RTC
and etc) is not completing operation correctly.
06
Slave Device Busy
The device can’t execute requested operation at
this time. Busy in another analogue operation.
Master has to repeat the same request at another
time.
