kkarr

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About kkarr

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  • Birthday 07/09/67
  1. Ken is somewhat correct in his answer.  I hate to dispute him, but unless you are not doing online programming with a  PLC5 and doing a monitoring/MMI type app like with RSView32 you can use any ethernet OPC server, like Kepware's AB Suite.  Since RSView32 is an OPC Client, it can work with a OPC Server.  I have done this several times.  However, the Kepware servers are about $800 for each server.  There are also the various ActiveX controls that will not work as Ken mentioned.  The key is to make sure you are getting a PLC5 ethernet OPC server and not plc doing programming through it.  I have worked with Kepware previously had have found their OPC server to be very good.  They are also a member of the OPC Foundation (www.opcfoundation.org).
  2. Opc

    Yes.  I would not start out by learning VC++ and COM/DCOM with OPC at the same time.  That's would be a big, frustrating learning curve.  If you want to learn VC++, start there and get comfortable with it first.
  3. Opc

    jonnie, That's quite a lengthy message.  I'll attempt to answer your questions.  First some background.  I have written multiple applications as OPC clients using VB, C++, and other tools like RSView32.  So, I'll attempt to address each issue. 1.  These statements are correct.  You basically set up the OPC Server PC to "point" toward (communicate with) the PLC/PLC Network or device through various means including the KT Card.  Another communication method is through ethernet if you have an ethernet supported PLC or device. 2.  Although OPC servers generally allow for "predefined" tags at the OPC server level, you don't normally have to do this.  The tags that the OPC clients use can normally be defined at the OPC client and can even be defined dynamically at runtime.  Tag read groups are important.  They define where the data is coming from within the OPC server and how they are to be updated. 3.  OPC clients are either local (on the same computer as the OPC server) or remote (a different computer from the OPC server).  Because of the technology used to develope OPC servers and clients, they can support remote access.  However some servers may have licensing issues with remote clients (i.e. RSLinx/RSLinx Gateway).  Because the client and server do not have to run on the same computer, it is possible to run accross the internet. However, it is not recommended.  There are a few issues such as bandwidth, slower update rates, and of course security.  So to answer your question about getting access from home over a cable modem, yes it can be done.  However, I would not recommend opening up your control system to the internet. 4.  As far as animation, you can use developement tools like RSView32, Iconics Genisis32, Intellution, and others.  You can also write custom code in VB, VC++, and other developement platforms.  This is all done using the OPC client interface. 5.  As mentioned earlier.  Quite simply, the answer is yes.  There are some ActiveX OPC client controls out there, or you can use the OPC API to the COM/DCOM interface directly.  I have used both VB and VC++. I hope this answers your questions.
  4. Ab ethernet/ip

    You know, when I made my previous post, I don't know why I didn't think of the router...must have been a long day or something.  Thanks Ken.
  5. Ab ethernet/ip

    When you want to talk to two subnets at the same time, you have to have multiple network cards, one for each subnet. Hopefully your OS and laptop hardware will be accomoding for another network card someplace (either PCMCIA slot or, if you have W2K/XP you can use a USB network card if your PCMCIA slots are taken).
  6. Swipe card access

    There are many swipe card readers available that do RS-232 and using the Comm port is probably the esiest.  However, if you want to take this application to the next level, you can also put the reader on a PC and tie it into a database.  The computer would then talk to the PLC.   You mentioned controlling access and recording who, when, and how much.  All of this could be recorded in the PC for later recall either by screen display, reports, automated email....you get the idea.  Some card reader companies even have their own developement/database tools to make application developement easier.   Although I've not used them, I was just looking at Mag-Tek (www.magtek.com) and all of their readers are RS-232.  They also have software and documentation online for review.
  7. Chris, Thanks for the ego boost.  I'm completely sold on OPC.  It's well worth any learning curve and actually it's not that hard to understand once you know it.  What makes it tricky when you're new is that there are few good tutorials.  (I've considered doing one).  Anyway, this forum has been interesting. Oh, I know what you mean about Linux.  I've got that at home.
  8. I don't remember if RSLinx Lite works with an OPC Client.  I do know that RSLinx Professional supports local (same computer) clients and RSLinx Gateway supports local and remote (another computer) OPC Clients.  OPC is an open standard, so you may want to order (for free) the OPC Standards CD from www.opcfoundation.org.  This will have a tech manual for using the VB interface.  Also more specifically for Rockwell, they have code samples here:  http://domino.automation.rockwell.com/applica....ocument If you need another OPC Server, another big supplier is Kepware (www.kepware.com) they have OPC Servers for many PLC's.  You can also download a 30 day, fully functional trial version. My first OPC Client program was fairly complex (10 clients. a lot of alarms, and a lot of data interaction.)  I had a bit of a learning curve for some of the stuff I did, but it was worth the time. For a cursory explaination of OPC look at http://www.cdi-mi.com/opc.htm