Using OPC Server to read and write directly to tags in RSLogix 5000

[Hisma 2]

Hello all Forgive me, for I am a newb when it comes to this. I do a fair bit of projects that require modifying ControlLogix PLC code, and then testing out the changes in a simulated environment before we go out and recommission the PLC. We have multiple PLCs in our workshop, but sometimes that is not enough to do a thorough testing, as there is tons of field IO that we obviously can't have in our test environment. We already use RSEmulate for doing simpler testing, but when we actually want to simulate IO, and how the PLC should respond to certain inputs coming in, it would be really nice if we could create apps/scripts that write values directly to the PLC tags, and then the script will in turn read in the returned values from the PLC and display them visually. I know you can come up with little DDE VBA scripts, but I dislike the "static" nature of excel spreadsheets, and would like to see if it's possible to develop something a little more advanced using open source tools out there. I am quite comfortable with java, and I see there is java OPC servers out there. I just want to know if anyone has taken on this sort of project, and if it's possible. Maybe there's already something out there we could purchase, or an open source project I could modify for our needs. Any info is appreciated!

[drx 2]

Hi, Yes, it is possible, with any langage as far as you have an OPC library included. My company has developped its own HMI with delphi and it works just fine. You can even do it through a real VBA application, by real I mean not the Xcel tool. Certainly with the .NET framework that would be quickly possible.

[PLCMentor.com 60]

For our simulation we generally write the logic in the PLC. The logic is in a separate routine or program so we can disable it before going "live." The simulation logic is designed to manipulate inputs and other feedback appropriately when your program logic requires it. So, for example, an output to start a motor in your logic would be used in your simulation rung to control the aux contact that would be received from your I/O. This generally allows testing of most sequences and equipment logic. You may need to inhibit any I/O in your system.

[mercedes98 0]

This is what you need http://www.inductiveautomation.com/

[Hisma 2]

Thanks for your answers guys. I like the idea of first checking out some open source java-based OPC server tools to start. I watched the vid on inductive SCADA. It sounds nice, but more than we need at this point. I realize I can accomplish the same goal making a "test" or "commissioning" software routine, but I just find that solution in-elegant, and opens you up to problems if your test routine has bugs in it. I like the idea of having an OPC server that can read/write tags directly, as the test is not modifying any existing code, just tag the tag values. Much less prone to error and makes the test environment less dependent on software modification... a good general testing practice. I just wanted to know if what I had in mind is actually possible... and it sounds like it is. Now to start researching the possibilities. Thanks!

[ravenloft12 0]

Gelecek HMI Components can help you. I have seen a new HMI components company. All components are OPC Client too. I mean you can write read bind to OPC Item (PLC address) via these components. I integrated to Visual Studio easily that components and I did not write any code. That company made some videos about usage and demo version of components.. You can try easily. Any way give you some screen of my project... www.geleceksoftware.com www.geleceksoftware.com

[DLB 0]

Sounds like you need OpenOPC: http://openopc.sourceforge.net/ We have an automated test framework written in Python that we use to create tests which poke the PLC and read back data to check that things are functioning as we expect. OpenOPC allows you to read and write data via any OPC server. It's very easy to use and so is Python if you haven't ever used it.