.ModelicaADS.Functions.ADS.funAdsReceiveReal .ModelicaADS.Functions.ADS.funAdsReceiveRealThis is a function to receive a Real value from a Beckhoff PLC via the ADS
protocol. The functions utilised from the C API provided by Beckhoff are
AdsSyncReadWriteReq(), AdsSyncReadReq() 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: Read the value of myOutputVar from in the PLC;
Step 3: Release handle of the variable in the PLC
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 myOutputVar.
// Receive double
int funAdsReceiveReal(double *p_RecvData)
{
long nErr; // Variable for error handling
ULONG lHdlVar; // lHdlVar
char szVar []={"MAIN.myOutputVar"}; // 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");
// Read the recvData from the PLC
nErr = AdsSyncReadReq(pAddr,
ADSIGRP_SYM_VALBYHND, // IndexGroup
lHdlVar, // IndexOffset
sizeof(*p_RecvData), // Size of data to received
p_RecvData); // Data to be received
if (DEBUG_FLAG != 0) ModelicaFormatMessage("Function to receive data called!\n");
if (nErr != 0)
{
ModelicaFormatMessage("Error: Function to receive data failed with code: %i\n",nErr);
return(1);
}
if (DEBUG_FLAG != 0) ModelicaFormatMessage("Function to receive 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 receive/right by handle in total successful! the data read is:\n");
if (DEBUG_FLAG != 0) ModelicaFormatMessage("The read data is %f\n",*p_RecvData);
return(0);
}
function funAdsReceiveReal input String varName "Name of variable to be read from PLC"; output Real recvData "buffer where incoming message is saved"; output Integer state "Error handling: 0 = OK!, 1 == Error, see simulation tab for info"; end funAdsReceiveReal;