NAME

       modbus_rtu_set_serial_mode - set the serial mode

SYNOPSIS

       int modbus_rtu_set_serial_mode(modbus_t *ctx, int mode);

DESCRIPTION

       The modbus_rtu_set_serial_mode() function shall set the selected serial mode:

       MODBUS_RTU_RS232
           the serial line is set for RS232 communication. RS-232 (Recommended Standard 232) is
           the traditional name for a series of standards for serial binary single-ended data and
           control signals connecting between a DTE (Data Terminal Equipment) and a DCE (Data
           Circuit-terminating Equipment). It is commonly used in computer serial ports

       MODBUS_RTU_RS485
           the serial line is set for RS485 communication. EIA-485, also known as TIA/EIA-485 or
           RS-485, is a standard defining the electrical characteristics of drivers and receivers
           for use in balanced digital multipoint systems. This standard is widely used for
           communications in industrial automation because it can be used effectively over long
           distances and in electrically noisy environments.

       This function is only supported on Linux kernels 2.6.28 onwards.

RETURN VALUE

       The function shall return 0 if successful. Otherwise it shall return -1 and set errno to
       one of the values defined below.

ERRORS

       EINVAL
           The current libmodbus backend is not RTU.

       ENOTSUP
           The function is not supported on your platform.

       If the call to ioctl() fails, the error code of ioctl will be returned.

AUTHORS

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