Żeby nie powielać poprzedniego schematu, na dobry początek zrobiłem swoją przejściówkę RS485-TTL wg. poniższego schematu:
Do mikrokontrolera ATmega32 wgrałem poniższy program:
[syntax=c]/*
* FreeModbus Libary: AVR Demo Application
* Copyright (C) 2006 Christian Walter <wolti@sil.at>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* File: $Id: demo.c,v 1.7 2006/06/15 15:38:02 wolti Exp $
*/
/* ----------------------- AVR includes -------------------------------------*/
#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>
#include <math.h>
/* ----------------------- Modbus includes ----------------------------------*/
#include "mb.h"
#include "mbport.h"
#include "temperature_sensors_agent_funnctions/tsa.h"
//#include "temperature_sensors_agent_funnctions/tsa.h"
/* ----------------------- Defines ------------------------------------------*/
#define REG_INPUT_START 1000
#define REG_INPUT_NREGS 10
#define REG_HOLDING_START 1000
#define REG_HOLDING_NREGS 10
/* ----------------------- Static variables ---------------------------------*/
static USHORT usRegInputStart = REG_INPUT_START;
static USHORT usRegInputBuf[REG_INPUT_NREGS];
static USHORT usRegHoldingStart = REG_HOLDING_START;
static USHORT usRegHoldingBuf[REG_HOLDING_NREGS];
void send_via_modbus(int *temperatures);
//uint8_t sensor_cnt;
//volatile uint16_t Timer1;
//uint8_t cel,cel_fract,subzero;
int temperatures[16];
uint8_t i;
/* ----------------------- Start implementation -----------------------------*/
int main( void )
{
init_timer();
DDRA |= (1<<0);
DDRA |= (1<<1);
const UCHAR ucSlaveID[] = { 0xAA, 0xBB, 0xCC };
eMBErrorCode eStatus;
eStatus = eMBInit( MB_RTU,0x0A, 0, 9600, MB_PAR_EVEN );
eStatus = eMBSetSlaveID( 0x33, TRUE, ucSlaveID, 3 );
sei( );
/* Enable the Modbus Protocol Stack. */
eStatus = eMBEnable( );
//init_sensors();
for( ;; )
{
( void )eMBPoll( );
//set_mb_regiters(temperatures);
//send_via_modbus(temperatures);
usRegHoldingBuf[0] = i++;
}
}
void send_via_modbus(int *temperatures){
uint8_t i = 0;
for(i=0; i<8; i++){
usRegHoldingBuf[i] = temperatures[i];
}
}
eMBErrorCode
eMBRegInputCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNRegs )
{
eMBErrorCode eStatus = MB_ENOERR;
int iRegIndex;
if( ( usAddress >= REG_INPUT_START )
&& ( usAddress + usNRegs <= REG_INPUT_START + REG_INPUT_NREGS ) )
{
iRegIndex = ( int )( usAddress - usRegInputStart );
while( usNRegs > 0 )
{
*pucRegBuffer++ =
( unsigned char )( usRegInputBuf[iRegIndex] >> 8 );
*pucRegBuffer++ =
( unsigned char )( usRegInputBuf[iRegIndex] & 0xFF );
iRegIndex++;
usNRegs--;
}
}
else
{
eStatus = MB_ENOREG;
}
return eStatus;
}
eMBErrorCode
eMBRegHoldingCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNRegs,
eMBRegisterMode eMode )
{
eMBErrorCode eStatus = MB_ENOERR;
int iRegIndex;
if( ( usAddress >= REG_HOLDING_START ) &&
( usAddress + usNRegs <= REG_HOLDING_START + REG_HOLDING_NREGS ) )
{
iRegIndex = ( int )( usAddress - usRegHoldingStart );
switch ( eMode )
{
/* Pass current register values to the protocol stack. */
case MB_REG_READ:
while( usNRegs > 0 )
{
*pucRegBuffer++ = ( unsigned char )( usRegHoldingBuf[iRegIndex] >> 8 );
*pucRegBuffer++ = ( unsigned char )( usRegHoldingBuf[iRegIndex] & 0xFF );
iRegIndex++;
usNRegs--;
}
break;
/* Update current register values with new values from the
* protocol stack. */
case MB_REG_WRITE:
while( usNRegs > 0 )
{
usRegHoldingBuf[iRegIndex] = *pucRegBuffer++ << 8;
usRegHoldingBuf[iRegIndex] |= *pucRegBuffer++;
iRegIndex++;
usNRegs--;
}
}
}
else
{
eStatus = MB_ENOREG;
}
return eStatus;
}
eMBErrorCode
eMBRegCoilsCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNCoils,
eMBRegisterMode eMode )
{
return MB_ENOREG;
}
eMBErrorCode
eMBRegDiscreteCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNDiscrete )
{
return MB_ENOREG;
}
//ISR(TIMER2_COMP_vect){
//
//uint16_t n;
//
//n = Timer1;/* 100Hz Timer1 */
//if (n) Timer1 = --n;
//
//}[/syntax]
Ogólnie program działa tj. master otrzymuje dane ze slave'a przy czym nie kiedy w Mbpool pojawia się błąd Write Error: Break Condition.
I tutaj moje pytanie jaka może leżeć przyczyna w tym błędzie?
Statystyki: Napisane przez MichalXY — 23 lip 2016, o 15:26
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