WEBfactory 2010

Set logging hysteresis in WEBfactory 2010Studio for signal „Buffer 1“ to 1 (or any other desired value)

Setting hysteresis inStudioWEBfactory 2010

Set logging parameters in WEBfactory 2010Studio for signal „Buffer1“ to Log Mode „OnChange“ (Log Conditions).

Setting the Log Contidions for the Buffer1 signal

Create VChannel signal with name e.g. „Buffer1Timeout“. Set Input Trigger for VChannel e.g. signal “Local Second” or “Local Hour”. Create VChannel Script as follows:

Sub GetResult()
   
'To avoid unneccessary triggering of the VChannel it is recommended to use the MODULO value of the 'trigger signal

    ' If ((X(1) Mod 5) = 0) Then

        Dim signalName              'Signalname of Log Item
        Dim logGUID                 'GUID of Log-Tags or name of Logging Tabelle
        Dim deathBandTimeSpan       'timespan for Timeout deadband
        Dim diffUTCLocalTime        'difference between UTC time and local time in seconds
        Dim currentSignalValue
        Dim res
 
        signalName = "Buffer 1"
        logGUID = "L_8D9998A3D1464A829AB07AE516D7C06A"
        diffUTCLocalTime = -7200
        deathBandTimeSpan = 5
        currentSignalValue = ReadSignal(signalName)  'get actual signal value
         
        res = CheckDeathBand(currentSignalValue, logGUID, deathBandTimeSpan, diffUTCLocalTime)
        Result = res
    ' End If
End Sub

Create function „CheckDeathBand“ in VChannel script library to have the function reusable. The function is built as follows:

'Function CheckDeathBand (currentSignalValue, logGUID, deathBandTimeSpan, diffUTCLocalTime) 

Dim cnnString
Dim sqlString
Dim ts
Dim result
 
    cnnString= DSN ' Connection String
    sqlString = "SELECT max([LoggingTime]) as MaxLoggingTime FROM [" & logGUID & "]"
 
    Set cn = CreateObject("ADODB.Connection")
    cn.Open cnnString       
 
    Set rs = CreateObject("ADODB.Recordset")
    rs.Open sqlString, cn, 0, 1
 
    If not rs.eof Then 
        If rs.fields("MaxLoggingTime").actualsize > 0 Then
            ts=cdate(rs.fields("MaxLoggingTime").value)
        End If
    end if
 
    rs.close
    Set rs = nothing
 
'check for last log entry is older than 5 seconds. (use h for hours)       
    If (datediff("s", ts, now()) + diffUTCLocalTime) > 5 Then	 
 
' create log entry when timeout is reached	
        cn.Execute  "INSERT INTO " & logGUID & " (LoggingTime,LoggingValue) VALUES (GETUTCDATE()," & replace(cstr(currentSignalValue), ",","." )  & ")"	
        result =  now() 
    Else
' if timeout is not reached just return last log timestamp
        result = ts
    End If
 
    cn.Close
    Set cn = nothing
 
    CheckDeathBand = result

'End Function

Creating the CheckDeathBand function