How to update variable in Workspace during simulation?

Hi all,

I have a simulink simulation that runs for 20s. At every 5s, it will generate a new set of data, which needs to be written to the workspace automatically. (Hence, the values in workspace should be updated automatically every 5s).

Right now, even though I try to write to the workspace every 5s, the values in the workspace remain at its initial value throughout the simulation and only update at the very end of the entire simulation time (i.e. after 20s).

May I know what should I do? Any advice or help is really greatly appreciated!

Best Regards, Rachel

Answer 1

[Kaustubha Govind]

I'm assuming that you are using something like the To Workspace block to write data to the workspace? I explained a little in my second paragraph over here, why I think that operation is not guaranteed to be completed until the end of simulation.

However, it seems (from your comment to the cyclist's answer) the broader issue is that you are attempting to update a block parameter based on a signal. Read this blog post to understand why that cannot be done.

[rach]

Hi Govind,

Thanks for the answer. Just a quick question, is there any matlab command that does the exact opposite as 'assignin', just that instead of assigning values to workspace variables, it reads variables out from the workspace?

Thank you so much for your time.

[TAB]

To read the value from specific workspace used "evalin" command.

See

>> doc evalin

Answer 2

[the cyclist]

I am not familiar with simulink, but will the assignin() command solve your problem?

>> doc assignin

[rach]

Hi,

Thanks for the reply! Yup, i managed to update variables in the workspace during simulation using the assignin function.

However, the simulink model consists of Three-Phase Parallel RLC Load that needs to read in the updated variables in the workspace into its 'Active Power P' box under the block parameters during the simulation. Is the set_param command able to solve the problem?

Thank you for your help!

[Homer Lan]

Hi, I met the same question with u. I want to update the value in the workspace when the simulink was running. And I use 'assignin',the value in the workspace can only save the initial value. And it cannot change with the simulation starting. How can I solve this? Thank you for your help!

[tq yu]

Hi , Lan ,have you solved your problem ?I have the datas in workspace that are time-updating ,how can i sen these datas to simulink models to achive rea-time simulation?Thks a lot