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.

       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 modbus_mapping_new() function shall return the new allocated structure if successful.
       Otherwise it shall return NULL and set errno.

ERRORS

       ENOMEM
           Not enough memory

EXAMPLE

           /* The fist 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)

AUTHORS

       The libmodbus documentation was written by Stéphane Raimbault
       <stephane.raimbault@gmail.com[1]>

NOTES

        1. stephane.raimbault@gmail.com
           mailto:stephane.raimbault@gmail.com