fl45.c

经典LabWindows CVI方面的教材《LabWindows CVI开发入门和进阶》一书例题1-4章中的源码

    
    checkErr( Ivi_LockSession (vi, VI_NULL));
    
        /* Set attributes: */
    viCheckParm( Ivi_SetAttributeViInt32 (vi, VI_NULL, FL45_ATTR_FUNCTION, 
                 0, measFunction), 2, "Measurement Function");
    viCheckParm( Ivi_SetAttributeViInt32 (vi, VI_NULL, FL45_ATTR_SECONDARY_FUNCTION, 
                 0, secondMeasFunction), 4, "Secondary Measurement Function");
                 
    /* 
        For the FL45, the resolution needs to be set before the range
        since the range is dependent on the resolution.
    */
    viCheckParm( Ivi_SetAttributeViReal64 (vi, VI_NULL, FL45_ATTR_RESOLUTION, 
                 0, resolution), 4, "Resolution");  
    viCheckParm( Ivi_SetAttributeViReal64 (vi, VI_NULL, FL45_ATTR_RANGE,      
                 0, range), 3, "Range");  

        /* Set the AC min/max frequencies only if configuring an AC measurement */
    switch (measFunction)
        {
        case FL45_VAL_AC_VOLTS:          
        case FL45_VAL_AC_CURRENT:        
        case FL45_VAL_AC_PLUS_DC_VOLTS:     
        case FL45_VAL_AC_PLUS_DC_CURRENT:
            viCheckParm( Ivi_SetAttributeViReal64 (vi, VI_NULL, 
                         FL45_ATTR_AC_MIN_FREQ, 0, acMinFreq), 
                         5, "AC Min Frequency");  
            viCheckParm( Ivi_SetAttributeViReal64 (vi, VI_NULL, 
                         FL45_ATTR_AC_MAX_FREQ, 0, acMaxFreq), 
                         6, "AC Max Frequency");  
            break;
        }

    checkErr( FL45_CheckStatus (vi));
    
Error:
    Ivi_UnlockSession(vi, VI_NULL);
    return error;
}

/*****************************************************************************
 * Function: FL45_ConfigureTrigger                                                       
 * Purpose:  Configures the common DMM trigger attributes.  These attributes 
 *           are FL45_ATTR_TRIGGER_SOURCE and
 *               FL45_ATTR_TRIGGER_DELAY.                                             
 *****************************************************************************/
ViStatus _VI_FUNC FL45_ConfigureTrigger (ViSession vi, ViInt32 triggerSource, 
                                         ViReal64 triggerDelay)
{
    ViStatus    error = VI_SUCCESS;
    
    checkErr( Ivi_LockSession (vi, VI_NULL));
    
        /* Set attributes: */
    viCheckParm( Ivi_SetAttributeViInt32 (vi, VI_NULL, FL45_ATTR_TRIGGER_SOURCE, 
                 0, triggerSource), 2, "Trigger Source");  
    viCheckParm( Ivi_SetAttributeViReal64 (vi, VI_NULL, FL45_ATTR_TRIGGER_DELAY,  
                 0, triggerDelay), 3, "Trigger Delay");  

    checkErr( FL45_CheckStatus (vi));
    
Error:
    Ivi_UnlockSession(vi, VI_NULL);
    return error;
}

/****************************************************************************
 * Function: FL45_ConfigureCompare                                         
 * Purpose:  Uses the value passed as the compare high and low values,then activates 
 *           Compare mode
 ****************************************************************************/
ViStatus _VI_FUNC FL45_ConfigureCompare (ViSession vi, ViBoolean compareEnable, 
                                         ViReal64 low, ViReal64 high)
    {
    ViStatus error = VI_SUCCESS;
    
    checkErr( Ivi_LockSession (vi, VI_NULL));
    
    checkErr( Ivi_SetAttributeViBoolean (vi, VI_NULL, 
              FL45_ATTR_COMPARE_ENABLE, 0, compareEnable));

    /* 
        Only set these attributes if the compare modifier is enabled. Else 
        setting these would be a waste of I/O time.                                                     
    */
    if (compareEnable)
        {
        viCheckParm( Ivi_SetAttributeViReal64 (vi, VI_NULL, FL45_ATTR_COMPARE_LOW, 
                                               0, low),  3, "Compare Low Value");
        viCheckParm( Ivi_SetAttributeViReal64 (vi, VI_NULL, FL45_ATTR_COMPARE_HIGH, 
                                               0, high), 2, "Compare High Value");
        }
    
    checkErr( FL45_CheckStatus (vi));
        
Error:    
    Ivi_UnlockSession (vi, VI_NULL);
    return error;
    }

/****************************************************************************
 * Function: FL45_ConfigureDecibel
 * Purpose:  Sets DMM to a decibel mode and sets the reference impedance.
 ****************************************************************************/
ViStatus _VI_FUNC FL45_ConfigureDecibel (ViSession vi, ViInt32 dbMode,
                                         ViInt32 impedance)
    {
    ViStatus error = VI_SUCCESS;
    
    checkErr( Ivi_LockSession (vi, VI_NULL));
    
    if (dbMode == FL45_VAL_DB_OFF)
        checkErr( Ivi_SetAttributeViInt32 (vi, VI_NULL, FL45_ATTR_DB_MODE, 
                  0, FL45_VAL_DB_OFF));
    else
        {
        /* 
            First set the dB Reference to the lowest value possible so that no
            error is generated when changing dB mode to a mode that has a smaller
            reference range.
        */
        checkErr( Ivi_SetAttributeViInt32 (vi, VI_NULL, FL45_ATTR_DB_REF, 
                  0, FL45_VAL_2_OHMS));
    
        viCheckParm( Ivi_SetAttributeViInt32 (vi, VI_NULL, FL45_ATTR_DB_MODE, 
                     0, dbMode), 2, "Decibel Mode Type");
        viCheckParm( Ivi_SetAttributeViInt32 (vi, VI_NULL, FL45_ATTR_DB_REF, 
                     0, impedance), 3,  "Decibel Reference Impedance");
        }
    
    checkErr( FL45_CheckStatus (vi));
        
Error:    
    Ivi_UnlockSession (vi, VI_NULL);
    return error;
    }

/****************************************************************************
 * Function: FL45_ConfigureHold                                            
 * Purpose:  Configures the DMM's hold capability.                                                   
 ****************************************************************************/
ViStatus _VI_FUNC FL45_ConfigureHold (ViSession vi, ViBoolean holdEnable, 
                                      ViInt32 holdThreshold)
    {
    ViStatus error = VI_SUCCESS;
    
    checkErr( Ivi_LockSession (vi, VI_NULL));

    viCheckParm( Ivi_SetAttributeViBoolean (vi, VI_NULL, FL45_ATTR_HOLD_ENABLE, 
                 0, holdEnable), 2, "Hold Enable");
    
    if (holdEnable)
        viCheckParm( Ivi_SetAttributeViInt32 (vi, VI_NULL, FL45_ATTR_HOLD_THRESHOLD,
                     0, holdThreshold), 3, "Hold Threshold");
    
    checkErr( FL45_CheckStatus (vi));
        
Error:    
    Ivi_UnlockSession (vi, VI_NULL);
    return error;
    }

/****************************************************************************
 * Function: FL45_ConfigureMinMax                                                 
 * Purpose:  Sets the DMM to min or max mode and set the appropriate value.
 ****************************************************************************/
ViStatus _VI_FUNC FL45_ConfigureMinMax (ViSession vi, ViInt32 minMax, 
                                        ViReal64 minValue, ViReal64 maxValue)
    {
    ViStatus    error = VI_SUCCESS;
    
    checkErr( Ivi_LockSession (vi, VI_NULL));
    

    if (minMax == FL45_VAL_MAX_MODE)
        {
        /* 
            Since we want to set both the minimum and the maximum attribute. 
            We first have to set the min-max modifier to min, set the initial 
            minimum, reset the min-max modifier to max, and then set the 
            initial maximum value. Any other way would cause configuration errors.
        */
        checkErr( Ivi_SetAttributeViInt32 (vi, VI_NULL, FL45_ATTR_MIN_MAX_MODE, 
                  0, FL45_VAL_MIN_MODE));
        viCheckParm( Ivi_SetAttributeViReal64 (vi, VI_NULL, FL45_ATTR_MIN_MAX_MIN, 
                     0, minValue), 3, "Minumum Value");
        viCheckParm( Ivi_SetAttributeViInt32 (vi, VI_NULL, FL45_ATTR_MIN_MAX_MAX, 
                     0, minMax), 2, "Min-Max Mode");
        viCheckParm( Ivi_SetAttributeViReal64 (vi, VI_NULL, FL45_ATTR_MIN_MAX_MAX, 
                     0, maxValue), 4, "Maximum Value");
        }
    else if (minMax == FL45_VAL_MIN_MODE)
        {
        /* Same comment as the "if" case in reverse other. */
        
        checkErr( Ivi_SetAttributeViInt32 (vi, VI_NULL, FL45_ATTR_MIN_MAX_MODE, 
                  0, FL45_VAL_MAX_MODE));
        viCheckParm( Ivi_SetAttributeViReal64 (vi, VI_NULL, FL45_ATTR_MIN_MAX_MAX, 
                     0, maxValue), 4, "Maximum Value");
        viCheckParm( Ivi_SetAttributeViInt32 (vi, VI_NULL, FL45_ATTR_MIN_MAX_MAX, 
                     0, minMax), 2, "Min-Max Mode");
        viCheckParm( Ivi_SetAttributeViReal64 (vi, VI_NULL, FL45_ATTR_MIN_MAX_MIN, 
                     0, minValue), 3, "Minumum Value");
        }
    else
        viCheckParm( Ivi_SetAttributeViInt32 (vi, VI_NULL, FL45_ATTR_MIN_MAX_MODE, 
                     0, minMax), 2, "Min-Max Mode");

    checkErr( FL45_CheckStatus (vi));
    
Error:    
    Ivi_UnlockSession (vi, VI_NULL);
    return error;
    }

/****************************************************************************
 * Function: FL45_ConfigureRelative                                            
 * Purpose:  Uses the value passed as the relative base value,then activates 
 *           Relative mode                                                   
 ****************************************************************************/
ViStatus _VI_FUNC FL45_ConfigureRelative (ViSession vi, ViBoolean relEnable, 
                                          ViReal64 value)
    {
    ViStatus error = VI_SUCCESS;
    
    checkErr( Ivi_LockSession (vi, VI_NULL));
    
    checkErr( Ivi_SetAttributeViBoolean (vi, VI_NULL, 
              FL45_ATTR_RELATIVE_ENABLE, 0, relEnable));
    
    if (relEnable)
        viCheckParm( Ivi_SetAttributeViReal64 (vi, VI_NULL, 
                     FL45_ATTR_RELATIVE_BASE, 0, value), 
                     2, "Relative Base Value");
    
    checkErr( FL45_CheckStatus (vi));
        
Error:    
    Ivi_UnlockSession (vi, VI_NULL);
    return error;
    }
                                                      
/*****************************************************************************
 * Function: FL45_Measure                                                         
 * Purpose:  Configures the specified measurement function, and reads the result.  
 *****************************************************************************/
ViStatus _VI_FUNC FL45_Measure (ViSession vi, ViInt32 measFunction, 
                                ViInt32 maxTime, ViReal64 *reading)
{
    ViStatus    error = VI_SUCCESS;

    checkErr( Ivi_LockSession (vi, VI_NULL));

    if (reading == VI_NULL)
        viCheckParm( IVI_ERROR_INVALID_PARAMETER, 4, "Null address for Reading.");

    viCheckParm( Ivi_SetAttributeViInt32 (vi, VI_NULL, FL45_ATTR_FUNCTION, 
                 0, measFunction), 3, "Measurement Function");  
        
    checkWarn (FL45_Read (vi, maxTime, reading));
    
        /* 
            Do not invoke the FL45_CheckStatus function here.  It is 
            invoked by the FL45_Read function. 
        */   

Error:
    Ivi_UnlockSession(vi, VI_NULL);
    return error;                         
}

/*****************************************************************************
 * Function: FL45_Read                                                            
 * Purpose:  Initiates a measurement and fetches the result.                 
 *****************************************************************************/
ViStatus _VI_FUNC FL45_Read (ViSession vi, ViInt32 maxTime, ViReal64 *reading)