Exception Responses; Examples - ABB C1300 User Manual Supplement

C1300
Advanced Circular Chart Recorder

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
Exception Response Name
Code
01 Illegal Function
02 Illegal Data Address
03 Illegal Data Value
07 Negative Acknowledgment
08 Memory Parity Error
Table 6.1 Exception Response Codes

6.1 Examples

A read register request to read holding register address 251 of slave 01 (undefined address for slave, beyond address limit) is shown
below.
Slave
Function
Address
01 03
The response returns exception response code 02, '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
IM/C1300–MOD Rev. C
The message function received is not an allowable action for the C1300.
The address reference in the data field is not an allowable address for the C1300.
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.
Register Start Offset
High Low
00 FA
Function
83
Exception Response Definition
Number of Registers
High Low
00 06
Exception Code
02
6 Exception Responses
Error Check Field (CRC-16)
E5
Error Check Field (CRC-16)
C0
F9
F1
13