Opc.......

Hello to all,

I was wondering (as so often): “Does anybody have an idea how OPC (server - client) works?” Well I was wondering how I can get the information from an OPC server into a website. A cheap (well if it doesn’t cost a lot of time) way to make a process visualised. Can somebody hand me some information or suggestions..??.... Maybe programming in VB6..???...

It's not OPC but if you have a PLC already the Cimrex line of HMI's by Biejer have built in Web (and FTP and e-mail) servers that allow you to publish process information from within the PLC to the Web. Very economical and more stable than a windows platform. For $1290 list you can get a 6" color touchscreen with web server/e-mail/ftp and if you really want, you can even show an exact copy of the HMI screen over the web with active buttons (this is probably too dangerous for most applications).

http://www.beijerelectronics.com/english/index.htm

They also have OPC but I haven't used it.

In full disclosure, I work for a copmpany that distributes Cimrex products.

nOrM

Check out these links.

Kepware They have a server you can download and run for two hours at a time, it comes with VB6 client examples.

OPCFoundation Lots of info and links.

OPCConnect more info and links.

You can do everything in VB if you want to. And there are probably lots of people (and maybe a forum somewhere) that could help you in this way.
But I think that it will cost you some time to do it yourself.

Most SCADA systems have a webserver option. But as this is an extra expense to the allready high expense of a full SCADA system it will be a bit pricey in the end. And you did say "cheap".

NetSCADA has a SCADA package that is fully webbased. Pricing is 3000 USD for a server and 3 clients.

A completely different way would be to use the webserver enabled ethernet modules that some PLCs have. I think that there quite a few people (and some on this forum) that are tinkering with this at the moment.

Merz EasyOPC is a lot less expensive at 544 USD per server license. It could be worth a look.

http://www.buildcoolstuff.com/topics/Web_based_robotics/14.shtml

This is a link that will show you how to get started in serial to cgi transfer. I have used this method in both linux and windows boxes using apache and iis web servers.

Best of all, it's free.

Good luck