Exception responses - GMP252

GMP252 User Guide

Document code
M211897EN
Revision
E
Language
English
Product
GMP252
Document type
User guide
Table 1. Modbus exception responses
Code Name Reason
01 ILLEGAL FUNCTION Unsupported function code
02 ILLEGAL DATA ADDRESS Register address or Object ID out of valid ranges
03 ILLEGAL DATA VALUE Otherwise invalid request

Accessing unavailable (temporarily missing) measurement data does not generate a Modbus exception. “Unavailable” value (a quiet NaN for floating point data or 8000hex for integer data) is returned instead. An exception is generated only for any access outside the applicable register ranges.