MODBUS_MAPPING_NEW(3) Libmodbus Manual MODBUS_MAPPING_NEW(3)NAMEmodbus_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 ALSOmodbus_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
libmodbus 3.1.0 10/06/2013 MODBUS_MAPPING_NEW(3)
