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MODBUS_MAPPING_NEW(3) libmodbus Manual 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 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 /* 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 modbus_mapping_free(3) modbus_mapping_new_start_address(3) AUTHORS The libmodbus documentation was written by Stphane Raimbault <stephane.raimbault@gmail.com> libmodbus v3.1.7 04/12/2025 MODBUS_MAPPING_NEW(3)
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLE | SEE ALSO | AUTHORS
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