Now You Can Have Robust Data Logging for Free – Part 12

Now You Can Have Robust Data Logging for Free – Part 12

HTML and Scripting Languages

We have the following accomplished:

PLC program
Visual Basic Program

Data collected in a Database
IIS web service established
ASP Script Written

Let’s take a closer look at the ASP Script ( AccRL.asp) that was written in part 11:

The <html> is at the start of the file, and the </head> is at the end. These tags all have to have a beginning and end. The ‘/’ indicates the end of the title.

The <head> is used to place the information for the web page. The refresh will load the page after 300 seconds (5 minutes). This way, the information will always be the latest. The title is used to label the page. This is the information at the top of the browser. The SHORTCUT ICON is used for the icon at the top of the browser near the page address.

<html>

<head>
<meta HTTP-EQUIV=”Refresh” CONTENT=”300″>
<title>ACC Automation – Robust Logger</title>
<LINK REL=”SHORTCUT ICON” HREF=”http://192.168.1.3/ACC_Do.ico”/></head>

ActiveX Data Objects (ADO) access databases from your web pages. ADOVBS.inc is a file that has all of the ADO constants defined. Be sure to add this file to your root web application directory.
<!– #include virtual=”/adovbs.inc” –>

The <% and %> symbols indicate the start and finish of the VBScript on the page. We dimension our variables for StartTime and EndTime. These will be used to determine how long our script took to execute.
<%
Dim StartTime, EndTime
StartTime = Timer

We dimension the variables used for the connection to the database file.
Dim OBJdbConnection
Dim rs1
Dim objCmd

We set up the connection to the database and determined what information we needed to retrieve.
Set OBJdbConnection = Server.CreateObject(“ADODB.Connection”)
OBJdbConnection.Open “Provider=Microsoft.ACE.OLEDB.12.0;DATA SOURCE=C:\AccRL\data\AccRL.accdb;Persist Security Info=False;”
set rs1 = Server.CreateObject(“ADODB.recordset”)
with rs1
.CursorType = adOpenForwardOnly
.LockType = adLockReadOnly
.CursorLocation = adUseServer
.ActiveConnection = OBJdbConnection
.Source = “SELECT * FROM Minute_Log;”
end with

Using getrows will allow us to execute the Select command and retrieve all the information from the database in one pass. This is the quickest method to get the information out quickly.
rs1.Open
arraytime = rs1.getrows()
rs1.close

We now write the information from the database to the page.
Response.Write arraytime(0,0) & “ ”
Response.Write arraytime(1,0) & “ ”
Response.Write Year(arraytime(1,0))& “/” & Right(“0” & Month(arraytime(1,0)), 2) & “/” & Right(“0” & Day(arraytime(1,0)), 2) & “ ”
Response.Write arraytime(2,0)& “ ”
Response.Write arraytime(3,0)& “ ”
Response.Write arraytime(4,0)& “ ”

The EndTime is now set, and the total time it took for the process is displayed.
EndTime = Timer
Response.write “Processing took “&(EndTime-StartTime)&” seconds ”
%>
</body>
</html>

ASP.Net Tutorial

Now that you have information in the database and IIS running, you can display the data in various ways.

Charts:

Graphs:

Gauges:

This ends our robust logger design. Please email me for the complete PLC program, VB source code, and web page file, and ask for the ACC Robust Logger Program. I will be happy to email you the information.

If you have any questions or need further information, please get in touch with me.
Regards,
Garry

If you’re like most of my readers, you’re committed to learning about technology. Numbering systems used in PLCs are not challenging to learn and understand. We will walk through the numbering systems used in PLCs. This includes Bits, Decimals, Hexadecimal, ASCII, and Floating Points.

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The ‘Robust Data Logging for Free’ eBook is also available as a free download. The link is included when you subscribe to ACC Automation.

HTML and Scripting Languages

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