.ModelicaADS.Functions.ADS.funAdsSendReal

Information

This is a function to send a Real value to a Beckhoff PLC via the ADS protocol. The functions utilised from the C API provided by Beckhoff are AdsSyncReadWriteReq() and AdsSyncWriteReq(). Errors are reported in the simulation tab.

The basic functioning is:
Step 1: Get the variable handle of the variable to be written on in the PLC;
Step 2: Write the value of sendData to the variable in the PLC;
Step 3: Release handle of the variable in the PLC

!!! Important !!!

Up to now the variable name of the input variable in the PLC is HARDCODED! This means the variable name in the PLC need to be exactly myInputVar.

C Source Code of Function

int funAdsSendReal(double sendData)
{
long        nErr; // Variable for error handling
ULONG        lHdlVar; // Variable to save handle
double *p_SendData = &sendData; // Pointer to variable which contains data to send
                
// HARDCODED variable name in PLC
char      szVar []={"MAIN.myInputVar"}; // Specify variable which should be written
unsigned long szVarLen = sizeof(szVar);

// Step 1: Get variable handle
nErr = AdsSyncReadWriteReq(pAddr,
                           ADSIGRP_SYM_HNDBYNAME,
                           0x0, 
                           sizeof(lHdlVar), 
                           &lHdlVar, 
                           szVarLen, 
                           szVar);
  if (DEBUG_FLAG != 0) ModelicaFormatMessage("Function to fetch handle called!\n");
if (nErr != 0){
ModelicaFormatMessage("Error: Function to fetch handle failed: %i\n",nErr);
return(1);}
  if (DEBUG_FLAG != 0) ModelicaFormatMessage("Function call to fetch handle sucessful!\n");
        
// Write the sendData to the PLC
nErr = AdsSyncWriteReq(pAddr, 
                       ADSIGRP_SYM_VALBYHND,// IndexGroup 
                       lHdlVar,// IndexOffset
                       sizeof(sendData),// Size of data to send
                       p_SendData);// Data to be send
        
  if (DEBUG_FLAG != 0) ModelicaFormatMessage("Function to send data called!\n");
if (nErr != 0){
  ModelicaFormatMessage("Error: Function to send data failed with code: %i\n",nErr);
  return(1);}
  
  if (DEBUG_FLAG != 0) ModelicaFormatMessage("Function to send data sucessful!\n");
  
//Release handle of PLC variable
nErr = AdsSyncWriteReq(pAddr,
                       ADSIGRP_SYM_RELEASEHND,
                       0,
                       sizeof(lHdlVar),
                       &lHdlVar); 
  if (DEBUG_FLAG != 0) ModelicaFormatMessage("Function to release handle called!\n");
if (nErr != 0){
ModelicaFormatMessage("Error: Function to release handle failed with code: %i\n",nErr);
return(1);}

  if (DEBUG_FLAG != 0) ModelicaFormatMessage("Function to release handle sucessful!\n");
  if (DEBUG_FLAG != 0) ModelicaFormatMessage("Function to write by handle in total successful! the data send is:\n");
                ModelicaFormatMessage("The send data is %f\n",sendData);
return(0);
} 

Interface

function funAdsSendReal
  input Real sendData "Data to be send as a real";
  input String varName "Variable Name in PLC";
  output Integer ans "Error handling: 0 = OK!, 1 == Error, see simulation tab for info";
end funAdsSendReal;

Revisions

• November 01, 2015  by Georg Ferdinand Schneider:
  Implemented
• January 30, 2016  by Georg Ferdinand Schneider:
  Revised for publishing