Examples

Serial Example

The following example sersimple.cpp shows how to configure a serial Modbus protocol and read values:

// Platform header
#include <stdio.h>
#include <stdlib.h>
#ifdef _WIN32
#  include <windows.h>
#else
#  include <unistd.h>
#endif

// Include FieldTalk package header
#include "MbusAsciiMasterProtocol.hpp"
#include "MbusRtuMasterProtocol.hpp"


/*****************************************************************************
 * Gobal data
 *****************************************************************************/

   const char *portName =
#if defined(_WIN32)
   "COM1";
#elif defined(__LINUX__)
   "/dev/ttyS0";
#elif defined(__MACOSX__)
   "/dev/ttys0";
#elif defined(__FREEBSD__) || defined(__NETBSD__) || defined(__OPENBSD__)
   "/dev/ttyd0";
#elif defined(__QNX__)
   "/dev/ser1";
#elif defined(__VXWORKS__)
   "/tyCo/0";
#elif defined(__SOLARIS__)
   "/dev/ttya";
#elif defined(__IRIX__)
   "/dev/ttyf1";
#elif defined(__OSF__)
   "/dev/tty00";
#else
   "/dev/tty";
#endif

//MbusAsciiMasterProtocol mbusProtocol; // Use this declaration for ASCII
MbusRtuMasterProtocol mbusProtocol; // Use this declaration for RTU


/*****************************************************************************
 * Function implementation
 *****************************************************************************/

void openProtocol()
{
   int result;

   result = mbusProtocol.openProtocol(portName,
                                      19200L, // Baudrate
                                      8,      // Databits
                                      1,      // Stopbits
                                      2);     // Even parity
   if (result != FTALK_SUCCESS)
   {
      fprintf(stderr, "Error opening protocol: %s!\n",
              getBusProtocolErrorText(result));
      exit(EXIT_FAILURE);
   }
}


void closeProtocol()
{
   mbusProtocol.closeProtocol();
}


void runPollLoop()
{
   short dataArr[10];

   for (;;)
   {
      int i;
      int result;

      result = mbusProtocol.readMultipleRegisters(1, 100,
                                                  dataArr,
                                                  sizeof(dataArr) / 2);
      if (result == FTALK_SUCCESS)
         for (i = 0; i < int(sizeof(dataArr) / 2); i++)
            printf("[%d]: %hd\n", 100 + i, dataArr[i]);
      else
      {
         fprintf(stderr, "%s!\n", getBusProtocolErrorText(result));
         // Stop for fatal errors
         if (!(result & FTALK_BUS_PROTOCOL_ERROR_CLASS))
            return;
      }

#ifdef _WIN32
      Sleep(1000);
#else
      sleep(1);
#endif
   }
}


#if defined(_WIN32_WCE)
int wmain()
#else
int main()
#endif
{
   openProtocol();
   runPollLoop();
   closeProtocol();
   return (EXIT_SUCCESS);
}

MODBUS/TCP Example

The following example tcpsimple.cpp shows how to configure a MODBUS/TCP protocol and read values:

// Platform header
#include <stdio.h>
#include <stdlib.h>
#ifdef _WIN32
#  include <windows.h>
#else
#  include <unistd.h>
#endif

// Include FieldTalk package header
#include "MbusTcpMasterProtocol.hpp"


/*****************************************************************************
 * Gobal data
 *****************************************************************************/

const char *hostName = "127.0.0.1";
MbusTcpMasterProtocol mbusProtocol;


/*****************************************************************************
 * Function implementation
 *****************************************************************************/

void openProtocol()
{
   int result;

   mbusProtocol.setTimeout(8000);
   mbusProtocol.setClosingTimeout(30 * 1000);
   result = mbusProtocol.openProtocol(hostName);
   if (result != FTALK_SUCCESS)
   {
      fprintf(stderr, "Error opening protocol: %s!\n", 
              getBusProtocolErrorText(result));
      exit(EXIT_FAILURE);
   }
//   mbusProtocol.setRetr;
}


void closeProtocol()
{
   mbusProtocol.closeProtocol();
}


void runPollLoop()
{
   short dataArr[3];
   int i;
   int result;
   DeviceIdObjectList objList;

   result = mbusProtocol.readDeviceIdentification(1, 1, 0, &objList);
   if (result == FTALK_SUCCESS)
      printf("Device ID OK.");
   else
      fprintf(stderr, "%s!\n", getBusProtocolErrorText(result));

#if 0
   for (;;)
   {
      result = mbusProtocol.readMultipleRegisters(1, 1,
                                                  dataArr,
                                                  sizeof(dataArr) / 2);
      if (result == FTALK_SUCCESS)
         for (i = 0; i < int(sizeof(dataArr) / 2); i++)
            printf("[%d]: %hd\n", 100 + i, dataArr[i]);
      else
      {
         fprintf(stderr, "%s!\n", getBusProtocolErrorText(result));
         // Stop for fatal errors
//         if (!(result & FTALK_BUS_PROTOCOL_ERROR_CLASS))
//            return;
      }
#ifdef _WIN32
      Sleep(10000);
#else
      sleep(1);
#endif
   }
#endif
}


#if defined(_WIN32_WCE)
int wmain()
#else
int main()
#endif
{
   openProtocol();
   runPollLoop();
   closeProtocol();
   return (EXIT_SUCCESS);
}