public static MeasuredValue ConvertTo(string name, DateTime timeStamp, string valueAsText, TypeCode targetType)
{
MeasuredValue mv = new MeasuredValue();
bool convertState = false;
mv.Name = name;
mv.TimeStamp = timeStamp;
switch (targetType)
{
case TypeCode.Boolean:
bool boolvalue = false;
convertState = bool.TryParse(valueAsText, out boolvalue);
mv.Value = boolvalue;
break;
case TypeCode.Int16:
Int16 i16value = 0;
convertState = Int16.TryParse(valueAsText, out i16value);
mv.Value = i16value;
break;
case TypeCode.Int32:
Int32 i32value = 0;
convertState = Int32.TryParse(valueAsText, out i32value);
mv.Value = i32value;
break;
case TypeCode.Int64:
Int64 i64value = 0;
convertState = Int64.TryParse(valueAsText, UsedNumberStyle, UsedCultureInfo, out i64value);
mv.Value = i64value;
break;
case TypeCode.Single:
float fvalue = 0;
convertState = float.TryParse(valueAsText, UsedNumberStyle, UsedCultureInfo, out fvalue);
mv.Value = fvalue;
break;
case TypeCode.Double:
double dvalue = 0;
convertState = double.TryParse(valueAsText, UsedNumberStyle, UsedCultureInfo, out dvalue);
mv.Value = dvalue;
break;
case TypeCode.String:
convertState = string.IsNullOrEmpty(valueAsText) == false;
mv.Value = valueAsText;
break;
default:
throw new Exception("type currently not supported: " + targetType.ToString());
}
if (false == convertState)
{
mv.Quality = OPCQuality.NoValue;
}
return(mv);
}
/// <summary>
/// Check all conditions and decide if the current should be written
/// </summary>
/// <param name="currentValue">the current measured value</param>
/// <param name="previousValue">the previous measured value </param>
/// <returns></returns>
public bool ShouldCurrentValueBeWritten(MeasuredValue currentValue, MeasuredValue previousValue)
{
if (currentValue == null)
{
throw new ArgumentNullException("currentValue");
}
if (previousValue == null)
{
throw new ArgumentNullException("previousValue");
}
_logger.DebugFormat("Previous value: {0}", previousValue.ToString());
_logger.DebugFormat("Current value: {0}", currentValue.ToString());
// OPCQuality.NoValue means that no value is available
// OPCQuality.NoValue should never be written to the database
// if current value is "NoValue" => don't write value
if (currentValue.Quality == OPCQuality.NoValue)
{
_logger.Debug("don't write value: OPCQuality = NoValue");
return(false);
}
// if the quality of the previous value was "NoValue"
// then write the current, because this is the first value ever
if (previousValue.Quality == OPCQuality.NoValue)
{
_logger.InfoFormat("write value (no previous value): {0}", currentValue.ToString());
return(true);
}
// both must be true to write value
if (CheckConditionTimeDeadBandIsMet(currentValue, previousValue))
{
if (CheckConditionValueDeadBandDeltaIsMet(currentValue, previousValue))
{
_logger.InfoFormat("write value: Current: {0} / Previous {1}", currentValue.ToString(), previousValue.ToString());
return(true);
}
}
// if all the conditions above are not meet, check if it is time to write a value
// but then set the current time to the current value
if (CheckConditionRewriteValueAfterIsMet(currentValue, previousValue))
{
currentValue.TimeStamp = DateTime.Now;
_logger.InfoFormat("write value (rewrite after): Current: {0} / Previous {1}", currentValue.ToString(), previousValue.ToString());
return(true);
}
return(false);
}
/// <summary>
/// Check if the condition "ValueDeadBandDelta" is met
/// Condition: The absolute difference between
/// the currrent and the previous value is bigger than
/// ValueDeadBandDelta
/// </summary>
/// <param name="currentValue">the current measured value</param>
/// <param name="previousValue">the previous measured value </param>
/// <returns></returns>
public bool CheckConditionValueDeadBandDeltaIsMet(MeasuredValue currentValue, MeasuredValue previousValue)
{
if (currentValue == null)
{
throw new ArgumentNullException("currentValue");
}
if (previousValue == null)
{
throw new ArgumentNullException("previousValue");
}
if (ValueDeadBandDelta == 0)
{
_logger.DebugFormat("ValueDeadBandPercentIsMet: ValueDeadBandPercent = {0}", ValueDeadBandDelta);
return(true);
}
bool equal = currentValue.Value.ToString() == previousValue.Value.ToString();
if (equal)
{
return(false);
}
double result = 0;
double value1 = 0;
double value2 = 0;
switch (currentValue.GetTypeCode())
{
case TypeCode.Double:
value1 = (double)previousValue.Value;
value2 = (double)currentValue.Value;
break;
case TypeCode.Int32:
value1 = Convert.ToDouble((int)previousValue.Value);
value2 = Convert.ToDouble((int)currentValue.Value);
break;
default:
return(true);
}
if (value1 > value2)
{
result = value2;
value2 = value1;
value1 = result;
}
result = Math.Abs(value2 - value1);
_logger.DebugFormat("ValueDeadBandDeltaIsMet: {0} Result: {1} %: {2}", result > ValueDeadBandDelta, result, ValueDeadBandDelta);
return(result > ValueDeadBandDelta);
}
/// <summary>
/// Check if the condition "TimeDeadBand" is met
/// Condition: The previous value was written before
/// "now" - TimeDeadBand
/// </summary>
/// <param name="currentValue">the current measured value</param>
/// <param name="previousValue">the previous measured value </param>
/// <returns></returns>
public bool CheckConditionTimeDeadBandIsMet(MeasuredValue currentValue, MeasuredValue previousValue)
{
if (currentValue == null)
{
throw new ArgumentNullException("currentValue");
}
if (previousValue == null)
{
throw new ArgumentNullException("previousValue");
}
TimeSpan sp = currentValue.TimeStamp - previousValue.TimeStamp;
if (sp.TotalSeconds > TimeDeadBand.TotalSeconds)
{
_logger.DebugFormat("TimeDeadBandIsMet: {0} > {1}", sp.TotalSeconds, TimeDeadBand.TotalSeconds);
return(true);
}
return(false);
}
/// <summary>
/// Check if the condition "RewriteValueAfter" is met
/// Condition: The previous value was written earlier than
/// "now" - RewriteValue
/// </summary>
/// <param name="currentValue">the current measured value</param>
/// <param name="previousValue">the previous measured value </param>
/// <returns></returns>
public bool CheckConditionRewriteValueAfterIsMet(MeasuredValue currentValue, MeasuredValue previousValue)
{
if (currentValue == null)
{
throw new ArgumentNullException("currentValue");
}
if (previousValue == null)
{
throw new ArgumentNullException("previousValue");
}
TimeSpan sp = currentValue.TimeStamp - previousValue.TimeStamp;
if (RewriteValueAfter.TotalSeconds < sp.TotalSeconds)
{
_logger.DebugFormat("RewriteValueAfterIsMet: {0} < {1}", RewriteValueAfter.TotalSeconds, sp.TotalSeconds);
return(true);
}
return(false);
}
