Which version of RSLinx should I go for it?

Can anyone please recommend the correct version that we should use if :

1) Wonderware communicating with CLX on ENET
2) Wonderware communicating with CLX on DH+
3) Citect communicating with CLX on ENET
4) CItect communicating with CLX on DH+

Thx in advance

I think the answer is:
1) Gateway
2) Gateway
3) Gateway
4) Gateway

All of those are OPC clients, right? If so, here's what I've learned:

If you want a remote OPC server, the answer is: Gateway.

RSLinx Professional can act as an OPC server on a "local machine." If you're going to be running RSLinx on the same computer as the HMI, this could be the way to go. In fact, you may be able to get away with an even "lesser" version of RSLinx.

AK

P.S. Talk to your AB representative about your application. There are MANY subtle nuances to CLX and OPC communications. Get them to verify that your application will work. If it's a really important project, call tech support and see if you get the same answers. Then, come back here and ask us what we think.

I was being inform by a programmer that for citect (V5) to communicae with CLX thru a 1784-PKTX, we do not need any RSLinx, there is a built in drivers in CItect, he's doing it with ENET comms. He said DH+ also built in

If this is true, people will save a few thousand on RSLinx Pro. correct me if i'm wrong. Thx.

Is Citect an OPC server, and does it support DH+?
If so, give it a try.

This is a good question. I am not aware of the capabilities of the CiTect CLX driver, so I will refrain from commenting directly about it. It MAY be perfectly ok for your application.

However RSLinx is a very extensive piece of software with many features. Many times I have seen engineers use in-built SCADA drivers because that is "how it comes, but later when RSLinx was introduced to them they never looked back.

As I recall you have posted here before asking questions about some fairly significant sounding projects with redundancy, etc; so I am guessing that this post also relates to the same. Also no-one uses CiTech on small or trivial systems. Akreel's comment are likely to be spot on; CLX comms has many subtle issues and you need to check with your AB tech people what is the best option for you.

PhilipW said:

As I recall you have posted here before asking questions about some fairly significant sounding projects with redundancy, etc; so I am guessing that this post also relates to the same.

Click to expand...

I'm glad Philip noticed this! If you are planning on building a redundant system, get help from Rockwell!!! I can't stress it enough, there ARE some interesting issues with CLX, OPC, and redundancy. If you don't get some advice, this could quickly become the trifecta of pain.

One thing to be aware of, for example: if you have redundant connections to your PLC you may end up using "Alias Topics." Alias topics are multiple paths to the same CPU. They can be switched when one path fails. Due to the nature of CLX communication, your alias topics will thrash about if you have them set to automatically switch on failure. You'll need to "switch on command" and write logic in the HMI to handle the switch. There's a technote on how to do it. This is KNOWN to occur in RSLinx. Citect could be better, or worse. As I understand it, it's the caused by the overhead required for buffering and tag name resolution in the CLX. It's a good bet you'll see it on other OPC server software.

AK

Wonderware's DAServer DASABCIP should accomodate you nicely without RSLinx. I have been using it here for a couple of months now for a small SCADA test app and it hasn't crashed yet.

Can't help with Citect though. Never used them.

Good Luck,
Jeff