Moxa Technologies IA262 Manual do Utilizador descarregar pdf (Página 60)

IA260/IA261/IA262/EM-2260 Linux User’s Manual Programmer’s Guide

Example to set the baudrate

#include <moxadevice.h>

#include <termios.h>

struct termios term;

int fd, speed;

fd = open(“/dev/ttyM0”, O_RDWR);

tcgetattr(fd, &term);

term.c_cflag &= ~(CBAUD | CBAUDEX);

term.c_cflag |= B4000000;

tcsetattr(fd, TCSANOW, &term);

speed = 500000;

ioctl(fd, MOXA_SET_SPECIAL_BAUD_RATE, &speed);

Example to get the baudrate

#include <moxadevice.h>

#include <termios.h>

struct termios term;

int fd, speed;

fd = open(“/dev/ttyM0”, O_RDWR);

tcgetattr(fd, &term);

if ( (term.c_cflag & (CBAUD|CBAUDEX)) != B4000000 ) {

// follow the standard termios baud rate define

} else {

ioctl(fd, MOXA_GET_SPECIAL_BAUD_RATE, &speed);

}

Baudrate inaccuracy

Divisor = 921600/Target Baud Rate. (Only Integer part)

ENUM = 8 * (921600/Target - Divisor) (Round up or down)

Inaccuracy =( (Target Baud Rate – 921600/(Divisor + (ENUM/8))) / Target Baud Rate )* 100%

E.g.,

To calculate 500000 bps

Divisor = 1, ENUM = 7,

Inaccuracy = 1.7%

* Inaccuracy should be less than 2% for work reliably.

Special Note

1. If the target baudrate is not a special baudrate (e.g. 50, 75, 110, 134, 150, 200, 300, 600, 1200,

1800, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600), the termios

cflag will be set to the same flag.

2. If you use stty to get the serial information, you will get speed equal to 0.

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Moxa Technologies IA262 Manual do Utilizador Página 60