RS 485 + komunikacni protokol ?

[Straka Matus]

> >
>
> Haluz ne, jen draze zaplacene poznani. Skuste poslat prvni bajt s natvrdo
> nastavenou paritou na 1 a druhy s paritou v 0.

No nizsie v maile su zdrojaky v C, ktorymi to realizujem. Na konci seriovej
linky je 8051 v MultiCPU rezime a funguje mi to. Ovsem prenosove medium je
kabel.

> protokol, treba jiz nekolikrat zminovany ProfiBus,
> a budu mit jistotu, ze to procpu dratama, TV rozvodem, vzduchem, modemem a
> pripadne temer cimko-li jinym.

O tom niet pochyb. V pripade, ze chceme pouzit este nejaky medziclanok,
naozaj nam neostane nic ine ako pouzit "standardny" protokol.

A teraz tie spomenute zdrojaky:

#define PORT1 0x2F8  /* Port Address Goes Here */
#define INTVECT 0x0B /* Com Port's IRQ here (Must also change PIC setting)
*/

/* Defines Serial Ports Base Address */
/* COM1 0x3F8                        */
/* COM2 0x2F8			       						 */
/* COM3 0x3E8			       						 */
/* COM4 0x2E8			       						 */

void send_address(unsigned char b)
{
	outportb(PORT1 + 3 , 43);  /* 8 Bits, Mark Parity , 1 Stop Bit */
					 /* 101011B */
	outportb(PORT1, b);	// Send address
	delay(3);
}

void send_data(unsigned char p)
{
	outportb(PORT1 + 3 , 59);  /* 8 Bits, Space Parity, 1 Stop Bit */
	outportb(PORT1, p); // Send Data
	delay(3);
}





void main()
{
	outportb(PORT1 + 1 , 0);        /* Turn off interrupts - Port1 */
	oldport1isr = getvect(INTVECT); /* Save old Interrupt Vector of later
recovery */
	setvect(INTVECT, PORT1INT);     /* Set Interrupt Vector Entry */
						/* COM1 - 0x0C */
						/* COM2 - 0x0B */
						/* COM3 - 0x0C */
						/* COM4 - 0x0B */
	outportb(PORT1 + 3 , 0x80); 	 /* SET DLAB ON */
	outportb(PORT1 + 0 , 0x18);  	 /* Set Baud rate - Divisor Latch Low Byte */
						 /*         0x06 =  19,200 BPS */
						 /*         0x0C =   9,600 BPS */
						 /*         0x18 =   4,800 BPS */
						 /*         0x30 =   2,400 BPS */
	outportb(PORT1 + 1 , 0x0);     /* Set Baud rate - Divisor Latch High Byte
*/
	outportb(PORT1 + 3 , 0x03);     /* bolo 0x03, 8 Bits, No Parity, 1 Stop Bit
*/
	outportb(PORT1 + 2 , 0xC7);     /* FIFO Control Register */
	outportb(PORT1 + 4 , 0x0B);     /* Turn on DTR, RTS, and OUT2 */
	outportb(0x21,(inportb(0x21) & 0xF7));  /* Set Programmable Interrupt
Controller */										 /* COM1 (IRQ4) - 0xEF  */
								 /* COM2 (IRQ3) - 0xF7  */
								 /* COM3 (IRQ4) - 0xEF  */
								 /* COM4 (IRQ3) - 0xF7  */
	outportb(PORT1 + 1 , 0x01);     /* Interrupt when data received */
..
..
..
atd.
}

Matus Straka