OPC servers

Hi
I am currently looking into OPC servers, to act as a databridge from PLC's to a SCADA package, and have evaluated Kepware (which is pretty good). Can anyone recommend any others?

PLC's are Mitsi A series and Modicon TCP/IP, SCADA is Cimplicity HMI.

(I know the Cimplicity has its own drivers for these PLC's but am investigating alternatives)

Cheers

I personally would use the SCADA drivers wherever possible, others may argue but there you go, each to their own !!

Go to www.opcfoundation.org and there you will find what you´re looking for.

We use Kepware and have never had problems with it.

Do you want an OPC Server to port to other systems as well as the SCADA or is it just passing information?

Surely if it is the latter you should be talking direct and not involving a third party, as suggested by tragically1969.

As with electrical system the least number of connections the better. You are merely introducing another variable for failure.

Jon.

Kepware is quickly becoming the standard. Rockwell, Wonderware, and Inductive Automation all bundle a form of KepServerEX with their products. I'm also a fan of Matrikon - especially with all that Eric Murphy does for the OPC Foundation.

Make sure your SCADA package is fully OPC compliant before you contemplate using OPC. I have used some SCADA packages and even though they say they can function as an OPC client they don't really do it very well. If that is the case then you would be better off sticking with their direct drivers. Also I agree with Tragically1969 why introduce another level of complexity ?

tragically1969 said:

I personally would use the SCADA drivers wherever possible, others may argue but there you go, each to their own !!

Click to expand...

In the case of Cimplicity, I agree completely. Use the built-in drivers and eliminate a step in the process.
It is my understanding that Cimplicity also will be using Kepware for its OPC solution.

I looked at Kepware and Applicom for my OPC server. I decided to use Kepware because it is software. Applicom has both hardware and software, but it seems to perform better if you use the hardware. My choice was based on the fact that hardware changes all too often.

There's a reason that all the major players are going to OPC instead of supporting their own drivers. One driving factor is standardization - adhering to a common API is nothing compared to all the nugwork to set the background up, particularly with MS changing so frequently (SPs count too). Another is that specialized companies can do a better job. It's simply not worthwhile for them to support their own drivers. Also, driver quality really comes into play when you're dealing with a high performance system. Compare Rockwell's own RSLinx to Kepware in a concurrent when a system with concurrent nodes. RSLinx will not hold its own. These companies can support many changing devices and focus on optimizing communication.

For a small, simple setup - go with integrated drivers. Or, if you're using a hardware vendor branded HMI, that should work well. But for many cases, industry standardization (OPC) makes sense for PC<->PLC interoperability.

Dua Anjing said:

Make sure your SCADA package is fully OPC compliant before you contemplate using OPC. I have used some SCADA packages and even though they say they can function as an OPC client they don't really do it very well. If that is the case then you would be better off sticking with their direct drivers. Also I agree with Tragically1969 why introduce another level of complexity ?

Click to expand...

Hi
I am in the process of linking up approx 20 machines to a data collector system for logging of process values and current status visualisation.

I have already done similar things using Cimplicity HMI elsewhere in this plant.

I was looking at OPC as an alternative idea, with possible other benefits in the future. I have costed it out and native Cimplicity is cheapest option.

My other issue is that the DCOM of my laptop seems to be screwed so I am unable to establish OPC comms, and am not in a position to surrender it to my IT guys for a WEEK (for 1/2 days work??) for them to rebuild it.

DCOM, the antiquated technology that OPC-DA is based on, can be a huge pain.

This post from the IA forum discusses DCOM security issues. Notably,

For DCOM security issues
http://www.matrikonopc.com/support/knowledge-base.aspx
http://www.ascolab.com/downloads/dcom.chm

For DCOM logging and troubleshooting
http://support.microsoft.com/kb/892500

cjd1965 said:

Hi
My other issue is that the DCOM of my laptop seems to be screwed so I am unable to establish OPC comms, and am not in a position to surrender it to my IT guys for a WEEK (for 1/2 days work??) for them to rebuild it.

Click to expand...