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modbus_mapping_new() modbus_mapping_new() 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 ini- tialized to zero. This function is equivalent to a call of the modbus_map- ping_new_start_address <modbus_mapping_new_start_address.md> 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 <modbus_mapping_free.md> • modbus_mapping_new_start_address <modbus_mapping_new_start_ad- dress.md> modbus_mapping_new()
Name | Synopsis | Description | Return value | Errors | Example | See also
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