MODBUS_RTU_GET_SERIA(3) Libmodbus Manual MODBUS_RTU_GET_SERIA(3)NAMEmodbus_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 modbus_rtu_get_serial_mode() 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[1]>
NOTES
1. stephane.raimbault@gmail.com
mailto:stephane.raimbault@gmail.com
libmodbus 3.1.0 10/06/2013 MODBUS_RTU_GET_SERIA(3)