"duration" function in stateflow using fixed-point datatype for time

I created an mpt.parameter for a time variable. Since time is in ms, I assigned data type as fixdt(0,16,0.001,0)

time_s = mpt.Parameter;
time_s.CoderInfo.Alias = 'Ts';
time_s.Description = 'Time in ms';
time_s.DataType = 'fixdt(0,16,0.001,0)';
time_s.Unit = 's';
time_s.Value =  0.5;

Now in one of my stateflow transition between states, I need to use this time variable. i.e: [duration(t > 20) > time_s]

Matlab thowrs error as below:

In fi > non-fi, or non-fi > fi, the non-fi must be a constant. Transition '[durat...time_s]'"duration(t > 20) > time_s"

Component:Stateflow | Category:Coder error

Error while generating code for chart Chart.

ps: I need fixdt(0,16,0.001,0) since I need to generate fixed point code and cannot afford using single or double or any Integer type.

Is there a workaround for this? Thanks in advance

Answer 1

[stozaki]

't' is a reserved word of the double data type. Therefore, you cannot set attributes such as data type.

I thought that using the after function was one of the workarounds. I have attached a sample model.

Supported Symbols in Actions

[Renish Ramegowda]

Thanks for the reply.

As per your suggestion, I changed variable "t" to "out_t".

My requirement was to start timer only after "out_t > 20" and it should be true till the time "time_s" is elapsed.

I'm attaching the model for your reference.

[stozaki]

You can avoid errors by not using absolute time in the temporal operator inside the Chart block.

Or could you consider using fi objects?

% I have modified the answer.

[Renish Ramegowda]

Thanks again.

For me, the transition shall happen only after the point, t > 20 is true and then from that point 0.5 sec is completed. Also in between 0.5 sec timer running, if t > 20 condition becomes false, then the time needs to be reset.

for such scenerio, "duration" function was very useful but issue is, it wont accept fixed point data type for time value. For my requirement, all values can only be fixedpoint data type since floting values cannot be accepted in code generation

Question: Why "duration" function dont accept fixed datatype input?

[stozaki]

Temporal Logic,

When using Event-Based (tick/CLK): Positive integer

When using Absolute-Time (sec/msec): It is just a positive number, that is, a double type.

Control Chart Execution by Using Temporal Logic

So, My model uses Event-Based Temporal Logic. This is a workaround.