public static bool QualifyMetric(ref OpcMetric metric, Dictionary <string, object> cache)
{
if (PointHasGoodOrDifferentBadStatus(metric))
{
if (!cache.ContainsKey(metric.Measurement.Name))
{
cache.Add(metric.Measurement.Name, metric.OpcValue);
metric.Measurement.LastOpcstatus = metric.Opcstatus;
metric.Measurement.LastValue = metric.OpcValue;
}
else
{
object lastvalue;
cache.TryGetValue(metric.Measurement.Name, out lastvalue);
metric.Measurement.LastValue = lastvalue;
}
if (!PointIsValid(metric) || !PointMatchesType(metric))
{
// Set de default value for the type specified
l_logger.ErrorFormat("Invalid point: measurement.name<{0}>, measurement.path<{1}>, metric.value<{2}>", metric.Measurement.Name, metric.Measurement.Path, metric.OpcValue.ToString());
switch (metric.Measurement.DataType)
{
case "number":
metric.OpcValue = 0;
break;
case "boolean":
metric.OpcValue = false;
break;
case "string":
metric.OpcValue = "";
break;
default:
l_logger.Error("No valid datatype, ignoring point");
break;
}
return(false);
}
}
// Check for deadband
if (PointIsWithinDeadband(metric))
{
return(false);
}
if (!PointMatchesType(metric))
{
l_logger.ErrorFormat("Invalid type returned from OPC. Ignoring point {0}", metric.Measurement.Name);
return(false);
}
return(true);
}
static bool PointHasGoodOrDifferentBadStatus(OpcMetric p)
{
var curr = p.Opcstatus;
var prev = p.Measurement.LastOpcstatus;
if (curr == "Good" || curr != prev || curr == "S_OK")
{
return(true);
}
return(false);
}
static bool PointMatchesType(OpcMetric metric)
{
var match = (metric.OpcValue.IsNumber() && metric.Measurement.DataType == "number") ||
metric.OpcValue.IsBoolean() && metric.Measurement.DataType == "boolean" ||
metric.OpcValue.IsString() && metric.Measurement.DataType == "string";
if (!match)
{
//log here
}
return(match);
}
static bool PointIsWithinDeadband(OpcMetric metric)
{
// some vars for shorter statements later on.
var curr = metric.OpcValue;
var prev = metric.Measurement.LastValue;
var dba = metric.Measurement.DeadbandAbsolute;
var dbr = metric.Measurement.DeadbandRelative;
// return early if the type of the previous value is not the same as the current.
// this will also return when this is the first value and prev is still undefined.
if (curr.GetType() != prev.GetType())
{
return(false);
}
// calculate deadbands based on value type. For numbers, make the
// calculations for both absolute and relative if they are set. For bool,
// just check if a deadband has been set and if the value has changed.
if (curr.IsNumber())
{
if (dba > 0 && Math.Abs(System.Convert.ToDecimal(curr) - System.Convert.ToDecimal(prev)) < dba)
{
return(true);
}
if (dbr > 0 && Math.Abs(System.Convert.ToDecimal(curr) - System.Convert.ToDecimal(prev)) < Math.Abs(System.Convert.ToDecimal(prev)) * dbr)
{
// console.log("New value is within relative deadband.", p);
return(true);
}
}
else if (curr.IsBoolean())
{
if (dba > 0 && prev == curr)
{
// console.log("New value is within bool deadband.", p);
return(true);
}
}
else if (curr.IsString())
{
return(true);
}
return(false);
}
static bool PointIsValid(OpcMetric p)
{
// check if the value is a type that we can handle (number or a bool).
return((p.OpcValue != null && (p.OpcValue.IsBoolean() || p.OpcValue.IsNumber())) || p.OpcValue.IsString());
}
