CRMCLink::FRegToLReg Method

Converts to an L register value from an intermediate form used when reading mixed F and L registers with ReadFFile.

Syntax

C++

static long FRegToLReg(

float regValue

);

Parameters

regValue

The value corresponding to an L register from the array of float data types returned by ReadFFile. Notice that this value is not usable at this stage. That is, it will appear to be a garbage value, until converted by this method.

Return Value

The L register value in a usable 32-bit integer format.

Remarks

This function is used when reading L registers from an RMC70, RMC150, or RMC200 using the ReadFFile method. Notice that this should only be done when the read is reading a mixture of L and F registers. Otherwise the ReadLFile method should be used to read exclusively L registers. Refer to the RMC70, RMC150 and RMC200 Register Data Types topic for details on L and F register types and on how to mix the two in a single read or write.

Example

The following code example illustrates the use of the FRegToLReg method.

C++

#include <windows.h>
#include <stdio.h>
#include "RMCLink.h"
 
void main()
{
    // In order to create COM objects, we must initialize the COM sub-system.
    ::CoInitialize(0);
 
    // Create a new RMCLink object.
    CRMCLink* pRMC = CRMCLink::CreateEthernetLink(CRMCLink::dtRMC70, _T("192.168.0.22"));
    if ( pRMC != NULL )
    {
        // Establish the connection.
        HRESULT hr = pRMC->Connect();
        if ( SUCCEEDED(hr) )
        {
            // Assume that the Indirect Data Map has been set up so that its
            // first four registers correspond to the following:
            //   F18:0 = Axis 0 Status Bits (L register)
            //   F18:1 = Axis 0 Error Bits (L register)
            //   F18:2 = Axis 0 Actual Position (F register)
            //   F18:3 = Axis 0 Target Position (F register)
 
            // Read up all four registers in a single read.
            float afData[4];
            hr = pRMC->ReadFFile(CRMCLink::fn70IndDataValues, 0, 4, afData);
            if ( SUCCEEDED(hr) )
            {
                // At this point, alData holds all four values. However, since
                // the first two were strictly L registers, they cannot be used
                // directly, since afData[0] would return a bogus floating point
                // value, and even (long)afData[0] would return a bogus long
                // value. Therefore, we use the FRegToLReg method. Notice that
                // the F register values are used normally.
                printf("Status Bits     = 0x%08X\n", CRMCLink::FRegToLReg(afData[0]));
                printf("Error Bits      = 0x%08X\n", CRMCLink::FRegToLReg(afData[1]));
                printf("Actual Position = %.3f\n", afData[2]);
                printf("Target Position = %.3f\n", afData[3]);
            }
 
            // Close the connection.
            pRMC->Disconnect();
        }
 
        // Free the RMCLink object we created.
        delete pRMC;
    }
 
    // Release the COM sub-system.
    ::CoUninitialize();
}