Desktop.DASH Web Content

1st February 2013

In this section we'll look at how to choose and configure the Web Content options that Desktop.DASH WEB can generate.

Preamble

Desktop.DASH v2 can produce either a very simple text only HTML web page, or a full sized text and graphics web page that attempts to mimic the actual dashboard displayed on your PC desktop.

DASH v2 can work in Desktop Mode (for direct control), Intranet Mode (for home wide control, using Tablets for example) and Internet / Instant Messenger Mode (for world-wide control with any web-connected device.)

Web Content Simple HTML File

At the time of writing the Device Mode web output is Read Only - meaning it's a view-able web page only - to change a value you must use the Instant Messenger feature.

CAUTION!

DASH can produce a very simple HTML web page, just like AlphaWebFX does, and by default, this file can be created in the project folder and can be viewed by browsing to and loading the web page using a Web Browser. This is an easy arrangement which is ideal for an in-house control system display that is safe and secure.

However, at the moment you allow access from the Internet to your control system, and it's utilities, for example, Desktop.DASH, you need to be aware of the risks and to adopt a much more robust approach to managing such information and resources to prevent abuse.

If your web page is exposed to the Internet then you need to serve it from a folder that is controlled by a Web Server. If you don't - then ANY other files in the same folder as the web page can be downloaded by anyone. For that reason, use Microsoft's IIS (Internet Information Services/Server), which is built right into Windows Xp and 7, both Home Premium and Professional.

To get started, create and test your dashboard, then select the Web Browser options by choosing Main Menu > Admin > Options... and then the Web Content TAB...

Web Content Options

From the dialogue you can set the required web content option. Device Mode produces a very simple tabulated text list of DataPoints and their values. Desktop Mode attempts to mimic the actual dashboard as you have configured it, placing some of the various display and control forms on a web page that may also include your selected background image. You will not get an exact rendition of the dashboard - just a close approximation.

By default the web content will be generated into the project folder. However, if you want to specify an alternate location (particularly if you intend to serve your content via a Web Server like IIS) then use the browse [ ... ] button and choose that folder. The file generated will be called default.html to suit the requirements of a typical web server's configuration.

To produce the required web content immediately press the [ Create Web Content ] button. This will generate the required file type and attempt to display that file in your default web browser. The created file will automatically refresh itself every minute or so, and Desktop.DASH is hard-wired to produce a new web page every minute or so, if this feature is enabled.

Desktop Mode (Advanced Feature)

In Desktop Mode, DASH will output a web page that can support button presses and value changes - but ONLY if that web page is served from an IIS Web Server, and a certain ASP.Net script, namely "processor.ashx" is present within the folder served by your IIS.

Desktop Mode Selected

If you want to be able to actually press buttons to turn stuff on or off, or adjust Integer values right on a live web page then select Desktop Mode. However, there are a number of steps required to make this possible - so only choose this option if you have the time and the patience to configure your system appropriately. In summary, you will need to do the following:-

Install IIS (Internet Information Services) on your Windows OS. (Free with Xp, Win 7 Home and Professional.) and configure it correctly.
Download and learn how to build an ASP.Net web site with Microsoft Visual Web Developer 2010 (to include client Authentication*).
Include "processor.ashx" as a handler on your web site (this file is freely available from XML Control as an ASP.Net Web Project) which formats web page clicks into COMMAND files recognized by Desktop.DASH

* You should include a "Log In" mechanism to prevent strangers from messing with your control system, maybe even include a white list of IP addresses, whatever it takes, before even allowing access to the actual web page produced by DASH. This is actually the hardest part of the job.

(Configuring IIS is beyond the scope of this text, a few Google's will get you started.)

Choosing Web Content Objects

Before you can use the Web Content feature you must actively select which objects are to be included in the created web page.

To do this, right-click any form object on the dashboard and choose Web Properties, for example...

Object Web Properties

...then check [ ] Allow Remote Reads to have that value included in the web content output.

Bear in mind, that by definition, any object selected in this way will also be remotely accessible via the Instant Messenger client too.

Notes

The Format Rule (e.g. ##.#) only affects the Instant Messenger response, and has no effect on the Web Content response;

The web content response will return the correctly formatted value as set from the right-click menu Setup > Value Formatting.

Set the required Unit of Measurement which will be reflected in both Instant Messenger and Web Content responses.

Only check [ ] Allow Remote Writes if you want the ability to change the value via Instant Messenger - or for changing values via the web page itself (See notes on using ASP.Net above to enable this feature.)

Transparent Back Color

The web content output in Desktop Mode also supports transparent back colors. The default (hard-wired) color to select transparency is Magenta...

Back Color Selection

So long as you choose, as shown, magenta as the back color, the output should yield an object with transparency, like this...

Transparent Object in Chrome Web Browser