Monday, April 28, 2014

No I/O server? No DA server? No problem!

OPC Unified Architecture is a technology that enables platform-independent communication. It is not Window-based like standard OPC-DA.  For example, it enables any OPC-UA client HMI to connect directly to field equipment like a PLC with no protocol translation or I/O server.  An additional benefit is that it is much more firewall-friendly than OPC-DA.

We now have a PLC that utilizes OPC UA.  The RXi controller for GE has upgraded their firmware to include an OPC UA server.  This article will explain how to set up that server to a Kepware OPC UA client.  Other client vendors include Wonderware, who recently released its OPC-UA client for System Platform 2014. 
1) The first step is to upgrade your RXi to the latest firmware version 8.11:


2) You will then need to download the program block and instructions to run the server:



3) Import the XML block into Machine Edition. (Make sure passwords are set to disable)

4) Add a call to_MAIN.

5) Assign the imported block to that CALL and assign variables to it.

6) Create a variable called TEST and make sure that it is Published External.

7) Download and start the PLC.
8) Set the UToffset to 300 and toggle the START. You should see the Running turn ON and the SERVER_STATUS got to a value of 2. 
9) Now the OPC UA server is ready. You could later add logic that would start the server if it has issues.
The next step is to add a Kepware OPC UA client. (Use default settings unless otherwise specified below)
10) Add the following Endpoint substituting your IP address.


11) Leave the username and password blank for now. This will create an Anonymous connection. You can also add security by setting the PLC up with a password and entering it here.

12)  Add a device for the PLC. (Use default settings unless otherwise specified below)

13) Click the select import items button.


14) Browse the Application-Variables folder and add the items you want to see.

15) Go into Quick Client and browse to the application folder to see your value.

Additional information about the setup can be found in chapter 13 of the RXICLT000 Manual.


No comments:

Post a Comment