You can use an enumeration data type for a datapoint or property. IzoT enumerations are defined as signed 8-bit types. Signed 8-bit enumerated types are not generally portable across different C compilers. To increase portability, the IzoT Interface Interpreter changes each enumeration to an assigned 8-bit scalar such as signed char, with C preprocessor definitions for the enumerated values.
The IzoT Interface Interpreter generates the following code for a SNVT_config_src datapoint type, which implements the config_source_t enumeration.
typedef signed char config_source_t #define CFG_NUL -1 /* enum config_source_t */ #define CFG_LOCAL 0 /* enum config_source_t */ #define CFG_EXTERNAL 1 /* enum config_source_t */ typedef config_source_t SNVT_config_src