How to export simulink data to workspace during simulation?

Question

I want to retrieve the data from simulink during simulation, and use serial network function to send these data to another program. Because I need to use another program to do some tricks and send command back to simulink, so I have to get data from simulink during runtime so that another program can make the right command.

I've tried using To Workspace block to export the data.

However, I can only got value in the very beginning of the simulation.

And I've also tried using scope and change some properties: check Save Data To Workspace and Uncheck Limite data to Last.

First, I started simulation, and I found the ScopeData didn't appear in the Workspace. Only when I stop simulation, ScopeData would appear in workspace.

And after that, I can use ScopeData.signals.values to get values.

But what I want is: when I start simulation, ScopeData would appear in workspace so that I can send these data to other program.

Does anyone know how to achieve this?

I found this page might be helpful, but I still don't know how to continuously export data during simulation.

Answer 1

Use get_param to read data from just at the current time. Also to send the data back to Simulink with set_param of a gain or another block.

An example of get_param

First load and start the simulation:

load_system('myModel')
set_param('myModel','SimulationCommand','Start');

To read data on any line of your simulink model:

1. Get a simulink block object (let's try a Clock with the name Clock):

   block = 'myModel/Clock';
   rto = get_param(block, 'RuntimeObject');
   

2. Then get the data on its first (or any) output port (or input) of that block.

   time = rto.OutputPort(1).Data;
   

You could do the reading, in a timer callback.

Also this might be helpful: Command Line Functionality for Simulink

Answer 2

During simulation Simulink stores logged data in an internal buffer and only writes the data to the Workspace when the simulation is paused or stopped. It sounds as if you really need to write an S-function (which will get signal values on a timestep-by-timestep basis) and communicate with Proteus that way.

Of course Simulink is a non-realtime simulator, so if you are talking about doing anything resembling real-time control then you are most likely taking the wrong approach altogether.

Answer 3

At any time during simulation you can force Simulink to write the simulation output data to the workspace:

set_param(bdroot,'SimulationCommand','WriteDataLogs');

I've found that this command is quite unstable in my Matlab 2010a for Win64. In particular I have to avoid it when simulation is stopped (i.e. first check get_param(bdroot,'SimulationStatus') ), otherwise Matlab shows an error and asks to be restarted.