Exception Responses; Examples - ABB DATUM L150 Operating Manual

6 EXCEPTION RESPONSES

The exception response codes sent by the slave are shown in Table 6.1. When a
slave detects one of these errors, it sends a response message to the master
consisting of slave address, function code, error code and error check fields.
Exception
Response
Code
01
02
03
07
08

6.1 Examples

A Read Register Request to read holding register address 100 of Slave 01
(undefined address for Slave, beyond address limit).
Address Function
01 03
The slave replies with an exception response signifying an 'illegal data address'. To
indicate that the response is a notification of an error, the most significant bit of the
function code is set to 1.
Slave Address
01
Exception Response
Name
Illegal
Function
Illegal
Data Address
Illegal
Data Value
Negative
Acknowledgement
Memory
Parity Error
Table 6.1 Exception Response Codes
Register Register
Start Start
Offset Offset
High Low
00
Function
83
Exception Response
The message function received is not an allowable
function on the COMMANDER 100/150.
The address reference in the data field is not an
allowable address for the COMMANDER 100/150.
The value referenced in the data field is not allowable
in the addressed slave location.
The function just requested cannot be performed.
Parity check indicates an error in one or more of
the characters received.
Number
of
Registers
High
FA 00
Exception
02
Definition
Number Error
of Check
Registers Field
Low
06 E5
Error Check
C0
(CRC-16)
F9
(CRC-16)
F1
17