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MODBUS_NEW_RTU(3)              Libmodbus Manual              MODBUS_NEW_RTU(3)

NAME
       modbus_new_rtu - create a libmodbus context for RTU

SYNOPSIS
       modbus_t *modbus_new_rtu(const char *device, int baud, char parity, int
       data_bit, int stop_bit);

DESCRIPTION
       The modbus_new_rtu() function shall allocate and initialize a modbus_t
       structure to communicate in RTU mode on a serial line.

       The device argument specifies the name of the serial port handled by
       the OS, eg. /dev/ttyS0 or /dev/ttyUSB0. On Windows, it's necessary to
       prepend COM name with \\.\ for COM number greater than 9, eg.
       \\\\.\\COM10. See
       http://msdn.microsoft.com/en-us/library/aa365247(v=vs.85).aspx for
       details

       The baud argument specifies the baud rate of the communication, eg.
       9600, 19200, 57600, 115200, etc.

       The parity argument can have one of the following values

           o   N for none

           o   E for even

           o   O for odd

       The data_bits argument specifies the number of bits of data, the
       allowed values are 5, 6, 7 and 8.

       The stop_bits argument specifies the bits of stop, the allowed values
       are 1 and 2.

RETURN VALUE
       The modbus_new_rtu() function shall return a pointer to a modbus_t
       structure if successful. Otherwise it shall return NULL and set errno
       to one of the values defined below.

ERRORS
       EINVAL
           An invalid argument was given.

EXAMPLE
           modbus_t *ctx;

           ctx = modbus_new_rtu("/dev/ttyUSB0", 115200, 'N', 8, 1);
           if (ctx == NULL) {
               fprintf(stderr, "Unable to create the libmodbus context\n");
               return -1;
           }

SEE ALSO
       modbus_new_tcp(3) modbus_free(3)

AUTHORS
       The libmodbus documentation was written by Stephane 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_NEW_RTU(3)