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
");
	       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 3.0.3 						    05/26/2012							 MODBUS_NEW_RTU(3)