NAME

       modbus_rtu_get_serial_mode - get the current serial mode

SYNOPSIS

       int modbus_rtu_get_serial_mode(modbus_t *ctx);

DESCRIPTION

       The modbus_rtu_get_serial_mode() function shall return the serial mode currently used by
       the libmodbus context:

       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 available on Linux kernels 2.6.28 onwards and can only be used with
       a context using a RTU backend.

RETURN VALUE

       The function shall return MODBUS_RTU_RS232 or MODBUS_RTU_RS485 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.

AUTHORS

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