custom device Siemens PLC

[esplu88]

hi,

I am doing HIL-testing with NI Veristand. My hardware is a cRIO 9075 and siemens ET 200s PLC. I found an ethernet/IP add on for veristand:http://zone.ni.com/devzone/cda/epd/p/id/6337

However, as I understand, this will not work with siemens PLCs. Is there any configurations I can make on the ethernet/IP add-on which will make it work on siemens PLCs? 

any help is deeply appreciated. 

[Devin_K]

The Ethernet/IP custom device is only designed to work with certain AB PLCs (ControlLogix series).  Based on a quick search, it looks like your Siemens PLCs only communicate with Profibus / Profinet, so it won't be compatible with the Ethernet/IP addon.  You would probably need to use a C Series Profibus card and write the custom device and/or FPGA code to provide an interface for NI VeriStand.

[esplu88]

Thanks for the reply. Isnt profinet compatible with ethernet? Additionally, do I have to make any considerations when making a custom device for siemens PLC when I am using a cRIO to run the DLL file? More specifically, would there be a difference in making the custom device if my PC was directly connected to the PLC?

[esplu88]

I am also uncertain of how the mapping of the PLCs IOs to the model will differ from these two situations:

1. Computer using veristand; DLL-file running on windows and directly connected to the PLC

2.Computer using veristand; DLL-file running on the cRIO which again is connected to the PLC

The PLC will controll and regulate the modell in both situations 

[Devin_K · Accepted solution]

Don't confuse Ethernet/IP (Ethernet Industrial Protocol) with "Ethernet" (the physical layer it is built upon).  Both Profinet and Ethernet/IP are protocols built on top of the Ethernet physical layer, but aside from that, they are completely different protocols.

In regards to you question, NI VeriStand consists of an engine for running yout models, IO, etc.. and a host-side application for configuring and communicating with the engine.  Usually the engine will run on a real-time system (such as a CompactRIO or PXI system), but it is also possible to run the engine on your WIndows machine.  The downside of doing this is that Windows is not a real-time operating system, so you can't expect deterministic, jitter-free operation, which is usually required by RT test applications.

As far as implementation differences, your cRIO target is running a VxWorks operating system, which cannot call DLLs.  Instead, you will have to comile your models into an .out file.  If you are using the Mathworks Simulink®, NI VeriStand ships with a VxWorks .tlc file that can be selected from Real-Time Workshop.  If you're compiling your own C-based model, you will need to use the GNU tool chain for VxWorks.  You can find some instructions on how to do this here.

If you're running the VeriStand engine on cRIO, you would need to use a C Series Profibus or Profinet module  for communication with the PLC.  I don't have experience using these, but you would need to program the FPGA and probably write a custom device to interface the code to NI VeriStand.  If you're running the engine on Windows, there may be 3rd party drivers available for this sort of communication that you could then wrap up with a custom device.

[esplu88]

OK, thank you very much for your answers, they have been of great help. 

There is one last thing I need to ask in fear of that it has been a misunderstanding. As far as I can see, the cRIO 9075 has Ethernet as a physical layer, but I can't see in its system specifications that it uses Ethernet/IP as a communication protocol. Are you certain that the only way the ET 200s can communicate with cRIO 9075 is by the profibus module? 

[esplu88]

btw, core protocol has to be UDP.

[Devin_K]

No, I'm not familiar with the ET 200s, so I'm not sure what commuication options are available for it.  I saw Profinet/Profibus mentioned when I did a quick search before, but it's possible there are other means of communications as well.