typedef struct _modbus_mapping_t {
int nb_bits;
int start_bits;
int nb_input_bits;
int start_input_bits;
int nb_input_registers;
int start_input_registers;
int nb_registers;
int start_registers;
uint8_t *tab_bits;
uint8_t *tab_input_bits;
uint16_t *tab_input_registers;
uint16_t *tab_registers;
} modbus_mapping_t;