Any experience with thin-client technology ?

[fmulder]

We are working on an offer where we have 30+ clients. We are considering thin-client technology (and not web client) but have not yet done this before. (Yes, we sometimes use Remote Desktop mainly for services, but have never done 30+ thin-clients in a control room.)

Our main concerns would be:

* How many clients can you 'host' on a server
* How is the performance of the client (can we expect any negative effects like alarms not blinking regularly)

Our solution would consist of 3 or 4 virtualised terminal servers with 30 clients.

Can you please share your experiences. And do's and don'ts that would help us ?

share the fun
Frenk Mulder

[mkoller]

you are only talking about "remote desktop" here.
I would check out our ULC-UX solution

[fmulder]

You are probably right. Could you explain to me how this actually works so that I better understand any limitations
Are the graphics rendered on the server ? And how do the graphics appear in the browser ? Why wont the graphics show on an iPhone. Is that a choice by ETM or a limitation in Safari ?

Thanks for your suggestion

[leoknipp]

Hello,

please have a look at the WinCC OA help for 3.14.
There you can find information how it works, e.g. the following sentences have been copied from the help document.

When a browser tries to connect to the ULC UX - URL of the WinCC OA HTTP Server, the HTTP server returns the ULC UX web page and automatically starts a local WinCC OA UI manager. This server side UI manger uses the RFB protocol to transfer the QT drawing commands into HTML 5 interpretable data chunks. A Java Script library at Client side afterwards interprets those data chunks and draws the graphics in the browser.

Best Regards
Leopold Knipp
Senior Support Specialist

[mkoller]

Whereby this is no longer entirely correct.
The solution, once based on the RFB protocol, was heavily modified and enhanced, so you can no longer call it RFB protocol.
ULC-UX now uses a multi-canvas approach and applies client-side tile caching to be fast with low bandwidth usage.

About iPhone: it is a choice by ETM since there's a better solution: use the app from the app store

[Gertjan van Schijndel]

Why are you not considering the webclient technology? There are thin clients, which can be customized. So you could install the webclient on it, just as is possible with the Siemens industrial thin client (ITC).

[fmulder]

* The web client still requires a 'full' PC instead of a much lighter (Citrix or Terminal server) thin client. A thin client is much cheaper and has less maintenance
* The ULC-UX has its limitations (like multi-monitor support)

Right now, we are evaluating all options. No definite choice has been made

[Gertjan van Schijndel]

Of many thin clients the image can be customized, so you can add and use the webclient from a thin client.