i have a constant block in a simulink model; i would like to change its value during the simulation when a particular event occurred in a stateflow chart. how can i do it?
If the Stateflow chart output indicates when this event has occurred, or if you can add an additional output that toggles when the event occurs, loop this indicator back (possibly through a Unit Delay block) to the control input of Switch block. The two inputs to the Switch would be two Constant blocks containing the two different values.
If you must do this programmatically without modifying the model, take a look at the reference for the sim command. I should warn you that this may not be trivial to accomplish.
Also, if want to be able to modify the contents of a Constant block mid-simulation (i.e. make it tunable), you may have to turn off Simulink's optimization settings that inline invariant parameters.
You can also add a Slider Gain block between your constant block and the Stateflow block. This would allow you to change the value of the slider gain block during simulation, without the need to change the value of the constant block.
Related
I have two Matlab function blocks that one is producing zero signal for the other. I want to store the exact time that signal changes to one in another parameter in order to use it elsewhere.
How can I do it?
This type of functinality is achieved using a Triggered Subsystem, as per the image below,
The output of the trigger block will take on value of the input (which in this case is the simulation time) every time the trigger signal rises. Look at the parameters of the Trigger block inside the subsystem for other options such as falling edge, or both edge, triggering.
So what I'm trying to do is this: I have a simulink stateflow model. To display some stuff from this model I built a GUI. In this GUI I have a button that should set a flag to true when pressed, which I want to use inside my stateflow model to start a transition. So whenever I enter a certain state in the stateflow I set the value of the flag to false and I want it set to true when I push the button. Unfortunately I can't find any way to set a local parameter inside a stateflow from a GUI callback function. I've tried using datastore memory blocks, but even though I can set the value from inside the stateflow model, I can't set the value from the callback function of the GUI.
Help would be really appreciated!
I once built a similar GUI that I put in a test harness for a Simulink model.
To make this work and not intrude too much on the Simulink design I implemented as an "Level 2 Matlab S-Function".
This does imply som interfacing overhead (setting up the ports and their parameters), but you can get anything that you have as a signal in or out from the stateflow chart into such a block (you will probably need a z^-1 feedback loop if you both want to get the output and control input).
The GUI code can be called from the Start block and the values read in the "Update" segment. If the pushbutton is activated, save this in a variable that is evaluated in the Outputs function and then set the outport to indicate this event (with reset logic if needed).
Check the online help for Level 2 Matlab S-function and in particular the msfuntmpl_basic.m to get started.
Hope this helps. I would like to note that this requires that you limit your interactions to those for which the stateflow has input/output.
I want to feed the initial conditions in state space matrix block in simulink by using signals "from-go to signal blocks". I m trying it with signal blocks but some errors pop up at the end and it says that the signal variables used as initial conditions are all undefined variable. In other words there exists "Undefined function or variable".
Any help appreciated, thank you
I take it you are using the State-Space block. The "initial conditions" parameter for the block is just that, a parameter:
You need to understand the difference between a parameter and a signal: a parameter is something that is constant throughout the simulation (e.g. a variable in the MATLAB workspace), whereas a signal is something whose value is updated at each time step. You cannot use a "signal" to parameterise a block, it's not possible, you can only use a parameter. Hope that clears things up.
If I misunderstood your question, please provide more details, including which block(s) you are using and if possible a screenshot of the model and the relevant block parameters.
I have a matlab function block in simulink, but I want this block to operate only if the first (of two) input changes. When the second input changes without a change of the first input, the block must remain it's value. How can i implement this?
Use a "Memory" block and a comparison or a "Detect Change" block to detect the changes in your signal. Use an "Enabled Subsystem" and put your matlab function into it to have the possibility to disable it. Make sure you set the "Output when disabled" parameter of your output ports to the intended behaviour.
I substituted my originial question, the problem is still the same, but the conditions are now different. To review the original question, have a look at the revisions.
I'm looking for a way to interactively select the signals I want to get displayed in my scope Block. The Bus Selector Block with the property Output as Bus does exactly that. I can select all desired signals conveniently without changing any block or signal dimensions.
But the scope block can obviously not handle properly signal names of buses. Therefore my scope legends are wrong:
If I don't set the Output as Bus property and Mux the signal together into the scope block it displays the right signal names. But this is no option as I'd need to adjust the Mux-dimension according to the signals selected.
Are there any workarounds?
(A Floating Scope is no option either)