interfacing a split system on Simulink

[dmblfi357]

I am attempting to split a real life power system which I have simulated into Matlab Simulink. I have remotely controlled the system using LabView via TCP/IP and was successful. Now I want to split this power system at the load bus to make two separate systems from the whole. I need to know how to communicate efficiently both split systems with each other and in turn to LabView. Perfect communication between both systems is essential being that the first system's current, which includes the generator, is dependent on how much load is pulled by the second system. How can I achieve this communication between the two using NiSink I would Guess?

[Philip_Courtois]

Hi dmblfi357,

I'm not sure I quite understand what exactly you are asking for. I assume that you are already using the NI LabVIEW Simulation Interface Toolkit, and you seem to have things working between LabVIEW and one Simulink system, right? With the system split in two parts, do you have any issues using LabVIEW to communicate to each system? As far as I know, the two systems will have to communicate to each other directly through Simulink.

My guess is that you are using this tutorial to establish the connection to one system: Building a LabVIEW User Interface for a Simulink Model with the LabVIEW Simulation Interface Toolkit.

Does any of this not work? Let us know what doesn't work, thanks.

[dmblfi357]

Basically What I am trying to do is stream data across two systems.  The right  now is that I am going to have one main or system one which will contain the voltage source.  On system two, which is a separate saved file, I will have a load or impedance such as an inductor box or light bulb bank etc.  I want the two systems two operate as one system but system 1 depends on system 2 being how much current is being pulled depends on the load.  Without a voltage source streaming to system 2, no current is generated.  I have an example of a smaller system which contains a source, autotransformer, and inductor box.  I will to split the system right after the auto transformer and the second system will contain only the inductor box or load.  Being the Voltage source and Load are separate, how can I constantly relay the data to the load and back so that it now acts as one system.  Here is a picture of the smaller system

[Jeff M]

Thanks for the detailed description of your application, this sounds pretty interesting (and challenging!)  Could you please provide more details on how you are attempting to tackle this problem?  I.e please list all the software you are using (both from NI and Mathworks) and also what hardware devices are used in your system.  This is a rather abstract problem, so the more details you could provide the better.

Based on the description you have already provided, here is what I am assuming:

-  You have two PC's representing the two different sub-systems 

-  Perhaps one PC has a Real-Time Operating System running the Simulink Model with the LabVIEW Simulation Interface Toolkit

-  The other PC may be running Windows or RT OS (either one), performing part of the data acquisition or control

So if your goal is to simply synchronize the two by streaming data via TCP/IP from one computer to the other, you can use the TCP/IP functions in LabVIEW to do that.  For example, if you want to use LabVIEW Real-Time for this application, we have shipping examples that demonstrate this capability under Help>>Find Examples, then browse to  Toolkits and Modules>>Real-Time>>Communication>> "TCP Communication - Host Engine" and "TCP Communication RT Engine". 

I'm not sure what you mean by "Perfect Communication".  Do you require determinstic behavior or just accurate data representation?  Because naturally there is latency involved with using TCP/IP to pass data back and forth, but I don't think there's anyway around that when you have two separate systems trying to communicate.

Hope this helps!

Jeff M.

Applications Engineering

National Instruments