1998 pi system users’ conference pi on the web: a primer for pi users omicron consulting 1998 pi...

1998 PI System Users’ Conference

PI on the Web: A Primer for PI Users

Omicron Consulting



Why Put PI Data on Web Pages?

Cheap seats for occasional usersQuick access net-wideGet closer to your customers


Plain Vanilla vs. Rich Presentation

Plain VanillaAny browser, any platformNo special configuration at the clientAd hoc static slice of data

Rich PresentationRich features of PI & COMMore muscle on the clientConfiguration and licensing


Plain Vanilla HTML


How Does the User Get There?


Tools

Microsoft FrontPage for the gateway pageWYSIWYG editing of the table, form controls

Visual InterDev for the serverTools for managing data sourcesCode editor features for scripts

Forms 101

Start a form: specify an action

<form action="scripts/pi_gate.asp" method="POST">

<div align="center"><center>

The values of the form fields are passed to the ASP page as <name, value> pairs


Forms 101 (cont’d)

Use an HTML table to align input fields<table border="0" cellspacing="4" width="40%" ><tr>

<td width="50%"><font size="3" face="Arial"><strong>User ID:</strong></font></td>

<td width="50%" ><input type="text" size="20” name="UID" value="pidemo"></td></tr>

<tr>

<td width="50%"><font face="Arial"><strong>Password:</strong></font></td>

<td width="50%"><input type="password" size="20” name="pwd" value="pidemo"></td></tr>

<tr>

<td width="50%"><font size="3" face="Arial"><strong>Specify Tag:</strong></font><font face="Arial"> </font></td>

Other options: pick source names for different servers, views


Forms 101 (cont’d)

End the table, add a button to submit the form

</table>

</center></div><p align="center"><input type="submit"

name="B1" value="Retrieve Avgs"></p>

</form>


Browser

ReturnHTML

RequestHTML

HTML and ADO

HTTP

PI

WWW Server

IIS

Files

*.ASP

ADO

PI-ODBC

OLEDB

ASP: COM meets PI-ODBC

• Use Active Data Objects (ADO) to manipulate ODBC on the server

• Include SQL utilities





• Make a connection to an ODBC DSN

ConnectionString = "dsn=PISource;UID=" & Request("UID") & ";pwd=" & Request("pwd")

Set Connection = Server.CreateObject("ADODB.Connection")

Connection.Open ConnectionString


ASP - ADO (cont’d)

Format and execute a querytag = SQLEncode(Request("tag"))

start_time = SQLEncode(Request("start"))

end_time = SQLEncode(Request("end"))

SQLStmt = "SELECT value, pctgood "

SQLStmt = SQLStmt & "FROM piavg "

SQLStmt = SQLStmt & "WHERE tag = '" & tag & "' AND time >= DATE('" & start_time & "') "

SQLStmt = SQLStmt & "AND time <= DATE('" & end_time & "') AND timestep =RELDATE(""1h"") "

Set RS = Connection.Execute(SQLStmt)


ASP - ADO (cont’d)

Create table cells as you step through the data

<table border="4"><caption align="top"><strong>Hourly Averages</strong></caption>

<% CurrentRecord = 0

Do While CheckRS(RS)

If CurrentRecord = 0 Then %>

<tr>

<th><b>Value</b></th>

<th><b>Percent Good</b></th>

</tr>

<% End If %> <tr><td><%= RS("value") %></td>

<td><%= RS("pctgood") %></td></tr><% RS.MoveNext

CurrentRecord = CurrentRecord + 1

Loop %></table>


Plain Vanilla Part II: Displays

PI-ProcessBook 2.0 adds VBA scripting and the ability to save displays to Web related formats

Server-side app periodically saves a live display to a static-format file

ASP page generates a page with a link to the requested image


Tools

FrontPage to layout the gateway pageVisual InterDev

No visual component to the ASP, just scripts

PI-ProcessBook to configure display files, run the script


Plain Vanilla Displays: The Code<body>

<%

Rem Derive the proper PNG filename

imgname = "../pbimgs/" + Request("Display") + ".png"

Rem Save the filename for use outside this script scope

Session("PNGname") = imgname

%>

<p><img src="<%=Session("PNGname")%>"> </p>

</body>


Rich Presentation


You Are There!

Self-contained Starting parameters are defined in the pageDisplays are linked into the page

InteractiveScripts may allow users to modify page

parametersDisplays may update within the page


Requirements

WindowsInternet ExplorerPI-ProcessBook


Getting ProcessBook

Install from a self-extracting executableLarge fileLicensing issues

Add a link<a href="pb20b2.exe">Install PI-ProcessBook

2.0</a>

Make sure the .exe is not in a directory with execute permissions


Tools

Microsoft FrontPageWYSIWYG layout of the pageSyntax for embedded objects handled for you

PI-ProcessBook to configure display files


Embedding Displays in HTML

First embed an instance of the “PI Display Document”

<object id="Display" name="Display” classid="clsid:4F26B906-2854-11D1-9597-00A0C931BFC8” border="0" width="590" height="273></object>


Get the Component

Allow for component download<object id="Display" name="Display"

classid="clsid:4F26B906-2854-11D1-9597-00A0C931BFC8"

codebase="pbdctrl.ocx" border="0" width="590" height="273"></object>


Specify a Display

Provide the URL of a PI-ProcessBook display file

<object id="Display" name="Display"

classid="clsid:4F26B906-2854-11D1-9597-00A0C931BFC8"

codebase="pbdctrl.ocx" border="0" width="590" height="273"><param

name="DisplayURL" valuetype="ref" value="demo.pdi"></object>


Automate the Display

Two PropertiesDisplayURL to change display filesDisplay to access the display object model, e.g.,

MyDisplay.Display.SetTimeRange “*-4h”, “*-1h”


Security Issues

Plain vanillaSecurity is controlled on the serverASPs must have script or execute permissionISAPI DLLs must have execute permissionNo special requirements for the client

Rich PresentationOpen the PI port number in the firewall to

update a display outside the firewall


Summary

Pick a Suitable ModelCreate ASPs or HTMLSupport configuration

PI-ProcessBook network installationDisplay component downloadSecurity Issues

Create display files if needed

1998 pi system users’ conference pi on the web: a primer for pi users omicron consulting 1998 pi...

Documents