OPC Server Connection wiring

Hi,

OPC server(any make) can be connected to a PLC(any make)only through Ethernet?

Or

Can an OPC server establish communication by connecting to RS232 port of a PLC through serial port?

The capabilities of the OPC Server depend entirely on what the software vendor has developed.

Most modern OPC Servers use a vendor-specific application protocol over Ethernet.

But many of them use serial protocols on standard link layers like RS-232 or RS-485.

And many of them use proprietary protocols and link layers, like Data Highway Plus, Profibus, or Modbus Plus.

Thanks Ken, new infos...

But Ken, with my knowledge OPC has a standard to follow. So how can the vendors make OPC connection according their wish?

Hello,

The standard is between the OPC server and OPC client. The standard does not cover the OPC server to the end device (PLC/DCS/robot/machine/etc).

Its now Crystal Clear Mr. Mark, Thanks!

Hi,
You can use PortCom to connect RS232 com of Plc to Ethernet line
of the Server.

In the case of the server, specifically KepserverEX, you can have multiple channels running multiple connections. Think of the server as the means to connect the device (PLC) to the client (Software) If you have multiple devices the server acts as the means for connecting these devices. This is a software product. You will still need to address the phyical (hardware) connection from the device to the computer. The server enables the different protocols to speak to the client.

For instance if you are using the Allen Bradley Connectivity Suite, you can utilize all of the protocols available in that suite, whether Ethernet or Serial. Many of the Connectivity suites offer Ethernet connections so long as they are available in the manufacturer's hardware. A listing of the suites and available connections is available through the following link:

http://www.eternity-sales.com/Kepware/kepwaredownloads.htm

If you have devices from different manufacturers, you will require connectivity suites for those manufacturers as well.

In terms of what you are looking for will depend upon what your requirements are and therefore being able to address those requirements.

You will want to first determine if your client (HMI Software / Database) is OPC capable.

Second you will want to obtain a list of devices your customer is looking to connect to the client.

From there, we can determine the items (connectivity suites) you will require for this application.

So, more information is needed before addressing what is required.

Any OPC server can communicate with a PLC via any means - this has little to do with the OPC specification. This can be Ethernet, Serial, USB, smoke signals, whatever. The specification has more to do with how an OPC client (HMI, alarming application, SQL data logger, etc) can generically communicate with the device via that OPC server. This de-couples the driver from the client software.