Web page displaying PLC data

[tunnysting 0]

Alright all, not sure if this is the right forum but I'll give it a shot. I've had some success displaying data from a logix 5000 on an excel spreadsheet. I would like to make this data look more user friendly in the form of a web page but I don't know where to start. Is there any software that I need to use? Can I still pull data straight from the PLC and display it? Any help appreciated. Cheers. Edited 30 Mar 2008 by tunnysting

[BobLfoot 301]

The Sample code I posted shows how to use the DDE function of RSlinx and Excel VBA to collect data. This approach would allow you to display it on a form and not just in hotlinked cells. The next step would be to check out some of the OPC Rslinx sample code and use it to collect data. I am not fluent in PHP or Java but they can pull data from MySql datatbases and MySql can collect data from OPC sources like RSLinx when all is configured properly. Others have done what you describe - so hopefully they'll share.

[Nathan 7]

Sure, this is the right forum. edit - The Micrologix has a built in web server. Maybe something similar is offered for Control Logix? http://literature.rockwellautomation.com/i...um002_-en-p.pdf DDE with Excel is a cheap and relatively easy way to go. I consider it to be a reasonable way for a technical user to make life easier. It won't deal well with concurrency, and, from personal experience, I can tell you that providing it as a service for non-technical users will require some support. There are also security implications with this model. Also, bad juju when it comes to logging historical data. A PLC/OPC driven web page is a sweet way to go in that it provides concurrent access to process data to your entire network. It is scalable (multiple concurrent apps, Excel instances or single seat HMIs, for example, directly accessing the PLC can cause bad things to happen), easy to access without a setup procedure, and can be made secure. Many HMIs have a rudimentary builtin web capability, either included or sold as a plugin. While these aren't very flexible, they are easy to use. The web server is builtin and the content generated for you. This doesn't seem applicable based on your post, but it's good info to know. The main step to rolling your own web page is synchronizing the OPC server to an SQL Database. Writing your own code to access the PLC directly is possible, but I would highly discourage it. A program like FactorySQL will provide this "data bridge" functionality. There are a few programs that do this. Just make sure that they're easy to configure including a "bi-directional" capability if you have any registers that you need to update from the web page. An example would be a temperature setpoint that a user could change from a panelview or the web page. Every dynamic web site that I know of, including Internet sites and MrPLC.com, use database driven websites. You have an engine that runs on your web server that executes code then outputs HTML. Examples are: PHP, ASP, Cold Fusion, Java Servlets, and many others. If you're not comfortable writing code yourself you can use a builder like CodeCharge Studio. I will warn you - once users see that they can access data from anywhere they'll keep asking for expanded capabilities. One thing that web pages aren't good at is efficiently refreshing data and doing even simple animation. These can be accomplished with AJAX, Flash, or Java applications, but I'm guessing that you don't have a full time web developer on hand. That's really what led to the creation of FactoryPMI. If you want both the drag and drop WYSIWYG capabilities of an HMI coupled with the ability to run it anywhere on your network via a web browser that's the way to go. In summary - if you need a peek into your process for a couple of technical users, or users who have support on hand, DDE+Excel approach is free - just make sure "realtime" is your goal, not "historical" data. The easiest (not necessarily cheapest) way to display data in web pages may be to use a software package. The best way to roll your own pages is by using an OPC<->SQL "databridge" then creating your own dynamic web pages however you want. Edited 30 Mar 2008 by Nathan

[dcalderonv 0]

What do you know or sugest in order to do that? Tkanks Edited 30 Mar 2008 by dcalderonv

[tunnysting 0]

Thanks for replies all. Nathan, I'll try and work through your suggestions but expect more questions! Cheers.

[Nathan 7]

No problem, happy to help. What do you want the web page to do? Display realtime values, "history" tables or graphs? Read only values? Or setting setpoints, adjusting modes, etc? Your start should really be requirements driven.

[tunnysting 0]

Just display data from the PLC for a start and if possible at a later date place this data in a database so records could be accessed.

[paulengr 44]

Instead of the ENBT, there's an "EWEB" card that can display web pages directly from the CLX chassis. Browse the CLX "selection guide". It's right in there. If you want to go further (historical data, etc.) and you are just trying out, Inductive Automation lets you have full featured copies of their software. The hitch is that you can only run the data collection part of the system for 2 hours before you have to restart it. Their system is 100% Java based. You can run it applet style or as a traditional installable web application (with web-based automatic updating).

[Giz99 0]

A less expensive option may be to use one of the Red Lion HMIs or other controls. They can host a web page of the data you require and may work out less expensive then an AB card.