OPC Interface From Rockwell ControlLogix to Proprietary DCS

We have an OPC Server for our Proprietary DCS which is currently communicating (bi-directionally) with a Wonderware front-end, but I'd like to use this OPC Server to exchange bi-directional data with a Rockwell ControlLogix PLC.

Is RSLinx the Rockwell software I need to use to make this happen?

I won't tell you that RSLinx won't communicate with this Proprietary server, but I will tell you that Kepware probably will. Especially if you're Proprietary DCS is using Profibus, Modbus, or one of 60 other protocols.

From Rockwell Knowledgebase: "The Kepware OPC server expands FactoryTalk View Studio device connectivity options by introducing over 60 communication drivers. This technote provides step by step instructions on how to setup the Kepware OPC Server v4.5 and earlier to allow FactoryTalk View Machine Edition applications to connect to many third-party devices and controllers."

The standard RSLinx you get with programming software won't do. You need "licensed" version like Gateway or Single-node version.

Also, most importantly, just having two OPC server won't allow you to communicate between the two. You need some way to bridge the two servers. Kepware makes a product called LinkMaster that will do that, however, I urge you to think about this setup. How important is it? Would you rely on Windows based system to do this communication for you? Would you rather have a hardware based gateway instead? ProSoft, Redlion Datastation are all good options assuming that the DCS does support one of the protocol that a gateway can handle such as modbus.

Now, if you insist on keeping with OPC I would suggest not using RSLinx but rather Kepware. This is because Kepware have a OPC client option that let you skip what I call the "in-between-client" like the Linkmaster I mentioned prior. This way you end up with

<DCS OPC> - <Kep OPC Client Option> - <Kepware AB>

#1 for Kepware, Rockwell supply a form of kepware as you say with 60 drivers, however the proper Kepware has over 150 I believe, you can licence it by driver and add them as you go, you can download it as a trial and it will run for 2 hours, it is licensed based on the drivers or buy what they call a suite that contains I believe most drivers.

The proprietary DCS is using a proprietary protocol (over TCP/IP) to communicate amongst its Controllers. It can also communicate via ModBus, but only "under-the-hood" to I/O Controllers. In other words, that protocol is not "available" or "exposed to" the application programming environment. It is essentially "hard-coded" at a lower, hidden level.

But - like I said ... we have a Wonderware front-end that is talking to this OPC interface on the proprietary system, sending data bi-directionally, so (in theory) almost anything should work, right? OPC is supposed to be a layer that presents a protocol that other OPC-compliant software can talk to, right?

But OK - it sounds like Kepware is the way to go.

So if I install the OPC interface for the proprietary DCS on an existing Server sitting on the Process Network, then I would also install the Kepware OPC Client on this same machine (??), and then the "Kepware AB" software on the other Server which has connectivity to the subsystem (and PLC) I am trying to link to???

Is that right ... 3 pieces of software?

Since you are going to have a Windows machine in the middle. Why not have WonderWare read the CLX tags and then write them to the DCS?
Cleaner.

Another option is the Softing dataFEED OPC suite which supports OPC DA client, OPC UA client (to communicate with the DCS OPC Interface) and supports client functionality for CompactLogix and ControlLogix through EtherNet/IP symbolic client messaging. The dataFEED OPC Suite has an exchange functionality which would allow you to configure exchange tasks between data sources (such as OPC DA items or OPC UA nodes and Logix tags), and the exchange can be triggered by timers or when a value changes in the data source. The evaluation version can work for 72 hours so it is possible to do in-depth testing prior to buying a license.

To me it does not sound as if there is a need for the OPC Servers (one for the DCS, another for Rockwell) to be installed on separate PCs.

Ken Moore said:

Since you are going to have a Windows machine in the middle. Why not have WonderWare read the CLX tags and then write them to the DCS?
Cleaner.

Click to expand...

Having an OPC Client that only has the task of exchanging the data has the advantage that maintenance of the Wondwerware application will not stop the data exchange.

Colt Hero said:

So if I install the OPC interface for the proprietary DCS on an existing Server sitting on the Process Network, then I would also install the Kepware OPC Client on this same machine (??),

Click to expand...

The OPC Client for exchanging data could be on the same PC as the two OPC Servers.

Colt Hero said:

and then the "Kepware AB" software on the other Server which has connectivity to the subsystem (and PLC) I am trying to link to???

Click to expand...

Is there a reason why you want to install the other OPC Server on another PC ?
It is possible to exchange OPC data between different PCs. For OPC DA, the method is called DCOM, but DCOM is such a cludge that a market for dedicated "OPC tunnelling" software has developed. Kepware do have an OPC tunnelling component. You pay for it of course.

With the additional data-exchange, this SCADA/data-exchange PC will be very critical.
Be sure to have a backup of this PC, so that in case it is down you can quickly get up and running.