Reading data logs, Reading data logs -6, 2 reading data logs – Echelon i.LON 100 e2 Internet Server User Manual
Page 213

myXmlNodeList = myXML.SelectNodes("/iLONDataServer/NVL")
myXmlNode = myXmlNodeList.Item(NV_INDEX)
Const UCPTindex As Integer = 0
If myXmlNode.ChildNodes(UCPTindex).InnerText <> NV_INDEX _
Then MsgBox("FAILED")
End If
14.2.2.2
Reading Data Logs
The following programming sample invokes the DataLoggerRead function, using a static
XML string as input. It then parses the string returned by DataLoggerRead using an
XMLDocument object, and writes the information it extracts to a database using SQL. This
code includes comments explaining each step of this process.
'Create an instance of the
i.
LON100's WSDL file.
Dim ilon As New WebReference1.iLON100()
'Specify the IP location of the
i.
LON 100 by replacing the default
'“localhost” with the IP address used by the
i.
LON 100.
s = ilon.Url
ilon.Url = s.Replace("localhost", "10.5.250.59")
Dim ret As String
Dim data As String
'Create the XML string to be passed to DataLoggerRead. This program
'will read log entries from the Data Logger using index number 0.
data="
'Call DataLoggerRead and send the SOAP message.
ret = ilon.DataLoggerRead(data)
'Prepare to parse the XML string returned by the function. Create an
'XML document object to store the return string, and an Xpath navigator
'object to navigate through the string and return the properties you
'want.
Dim xmlDoc As New System.Xml.XmlDocument()
Dim xmlNav As System.Xml.XPath.XPathNavigator
'Parse the XML string returned by DataLoggerRead.
xmlDoc.LoadXml(ret)
xmlNav = xmlDoc.CreateNavigator()
'Create iterators to store the values you want to extract from the
'return string.
Dim dataValues As System.Xml.XPath.XPathNodeIterator
Dim timestamps As System.Xml.XPath.XPathNodeIterator
Dim pointNames As System.Xml.XPath.XPathNodeIterator
Dim locations As System.Xml.XPath.XPathNodeIterator
Dim source As System.Xml.XPath.XPathNodeIterator
Dim units As System.Xml.XPath.XPathNodeIterator
myXML.LoadXml(myXMLreturnString)
i.
LON 100 Internet Server Program
14-6
mer’s Reference