Read simulink signal data into matlab during simulation - matlab

I want to continuously read simulink signal data into the command line while the simulation is running. get_param() seems to be blocking so that doesn't quite work when put in an infinite while loop.
I'm now trying to use a UDP send block but I can't seem to receive data. My UDP block sends data to localhost over remote port 25000 and local port 25001.
In matlab I use the following code but it simply times out with no data
u=udp('127.0.0.1', 25001,'LocalPort',25000);
fopen(u)
fread(u)
fclose(u)
delete(u)
What are my options to continuously read out simulink signal data into Matlab CLI?

Control Simulation Using the "set_param()" command like follows:
set_param('sys','SimulationCommand','WriteDataLogs')
For a working example, type "sldemo_varsize_basic" in the matlab command window. Then above command becomes
set_param('sldemo_varsize_basic','SimulationCommand','WriteDataLogs')
If you set the simulation time to sufficiently large and start the simulation, the "simout, simout1", "tout" and "xout" variables are created/updated in the workspace every time you issue the command above.
Unfortunately, I was not able to find a good quality documentation of this feature.

Are you trying to store the value of your model outports DURING simulation? This is not possible because the variables 'simout, simout1", "tout","xout" etc are created only once simulation is OVER.
In order to read/store the value of outports during simulation, you will have to attach an 'Runtime Object' to the outports.
Refer 'Access Block Data During Simulation' in the Simulink documentation or see this link: http://in.mathworks.com/help/simulink/ug/accessing-block-data-during-simulation.html?s_tid=gn_loc_drop
Hope it helps :)
This question has already been answered here using RunTime Objects as I have described above:
https://stackoverflow.com/a/17006419/6580313

Related

Creating a TCP/IP Server block in simulink

I'd like to have a block in simulink that serves as a tcp server. Ideally the simulation would block when it hits this block, wait until data was transfered to it by the client, and than pass that data out to be used in that step of the simulation. I'd also like the connection to persist across function calls, if possible.
I got this to work in Matlab pretty easily, using the myConnectionObject=tcpip(.) and fread(..) functions. So I figured I could just initialize the connection in the workspace, wrap my freads() into a MATLAB function block in Simulink and I'd be on my way.
However, I'm having trouble getting the tcpip connection object into the function to be visible in Simulink so I can use it with fread(). Passing it through a "From Workspace" block gives an "Unsupported input format..." error.
Thanks,
The Matlab Function block is great for quick simple mathematical functions, but when it comes to initialization or some cleanup at the end of a simulation, a
s function is the right tool. With Start and Terminate you got your places to setup and close down the server within the block.

step by step simulation in command line for Matlab Simulink model

I want a solution for command line implementation for Matlab Simulink. In simulink model there is simulation switch called "step forward". With this I am able to run step by step and able to see the outputs in scope for each sample time.
I am also able to change some inputs for constant input blocks at any sample period time. However, I want to do this in command line, because I have a huge model and I want to reuse this model verification script.
I am able to do some thing like this using "sim" command. But the sim command is just simulating the entire model at once, and I could not observe/change the intermediate outputs/inputs. The "sim" command with a certain stop time is running for certain sample periods, but later if I give the next "sim" command, it is running from the beginning and not starting from where it stopped. But, is there any exact Matlab command to step and pause (for one sample period time) the simulation, like that in simulink gui.
You want to use SimState to save the states of the model at the end of one simulation, and restore them at the beginning of the next simulation. How to do this is described in the documentation under Save and Restore Simulation State as SimState.
You cannot make any structural changes to the model (e.g. add or remove block) between each call to sim. There are also a few blocks which don't support SimState, see the documentation for more details. Note that this is for the latest release (R2015a), more and more blocks were added to support SimState over the past few years, so you want to check the release notes depending on the release you are using.
You can try this:
sldebug('gcs');
you are now in debug mode, you can type in help to get an overview of the available commands. To run through the model type in:
next
Each time you type next, you move the simulation one step forwards.
The following link will provide you with further details on how stepping through a simulation works.
http://www.mathworks.com/help/simulink/ug/how-stepping-through-a-simulation-works.html
For more details on using the debugger to run through the simulation step by step you can go to:
http://www.mathworks.com/help/simulink/ug/running-a-simulation-step-by-step.html

How to plot data from scope that is used in external mode simulation?

I have a simulink model connected to my hardware and I am able to see the response on my scope when I change the setpoints in my model etc. But I will like to save this data from the scope so that later I can plot it.
I have read some documentation online but I am still confused. Can someone give me a step by step method on how to plot this data from the scope used in external mode.
Kind Regards
There is a write data to workspace block in simulink. You can put that block in the same bus as the scope and save the data to Matlab. If you want it automatically save into the disk, then I recommend to write a small .m script that takes this variable and saves in disk using save(). You can automatically run this .m file after the Simulink model is stopped (or some other condition you prefer) going to Properties->Callbacks and choosing the appropriate function callback.

How to export simulink data to workspace during simulation?

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.
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:
Get a simulink block object (let's try a Clock with the name Clock):
block = 'myModel/Clock';
rto = get_param(block, 'RuntimeObject');
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
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.
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.

1]Change variable value during script is running 2] while running Script in loop does not update variable value in workspace

I am controlling a pilot plant of boiler through Matlab using modbus RTU (serial communication).
I am running my control program (in editor) for 45 mins through a loop but I am facing two problems :
1] I can't change any variable value while running program which is deadly needed.
2] I am unable to see real time data in workspace while running script.
It updates all variables after finishing execution time. For my application I want data to appear for every iteration.
I couldn't solve them so I switched to simulink but that was even more frustrating.
In simulink I used user defined blocks (embedded Matlab function) to generate modbus address PDU which does not support to in-built matlab functions (like dec2hex).
Will please someone let me know in simulink, serial send/receive support which data format?(ASCII/HEX/DEC)
If you want to see the status of your system after each iteration this can be solved by putting a breakpoint there. If required you can even change the value of variables then.