modbus_mapping_new(3) ===================== NAME ---- modbus_mapping_new - allocate four arrays of bits and registers SYNOPSIS -------- *modbus_mapping_t* modbus_mapping_new(int 'nb_bits', int 'nb_input_bits', int 'nb_registers', int 'nb_input_registers');* DESCRIPTION ----------- The *modbus_mapping_new()* function shall allocate four arrays to store bits, input bits, registers and inputs registers. The pointers are stored in modbus_mapping_t structure. All values of the arrays are initialized to zero. This function is equivalent to a call of the linkmb:modbus_mapping_new_start_address[3] function with all start addresses to `0`. If it isn't necessary to allocate an array for a specific type of data, you can pass the zero value in argument, the associated pointer will be NULL. This function is convenient to handle requests in a Modbus server/slave. RETURN VALUE ------------ The function shall return the new allocated structure if successful. Otherwise it shall return NULL and set errno. ERRORS ------ *ENOMEM*:: Not enough memory EXAMPLE ------- [source,c] ------------------- /* The first value of each array is accessible from the 0 address. */ mb_mapping = modbus_mapping_new(BITS_ADDRESS + BITS_NB, INPUT_BITS_ADDRESS + INPUT_BITS_NB, REGISTERS_ADDRESS + REGISTERS_NB, INPUT_REGISTERS_ADDRESS + INPUT_REGISTERS_NB); if (mb_mapping == NULL) { fprintf(stderr, "Failed to allocate the mapping: %s\n", modbus_strerror(errno)); modbus_free(ctx); return -1; } ------------------- SEE ALSO -------- linkmb:modbus_mapping_free[3] linkmb:modbus_mapping_new_start_address[3] AUTHORS ------- The libmodbus documentation was written by Stéphane Raimbault