How to use and/or create a Timer

PRESENTATION

Prerequisites

• Have done the tutorial Start to use Sim4Sys with a simple model (blackbox),
• Have a look at Countdown page.

Skills that you will acquire

In this tutorial, you will learn two ways to model a timer:

1. via the VB's HMI Element "Countdown"
2. entirely inside Sim4Sys-Designer

At the end, we want a common behavior:

• Start a timer for several seconds,
• Be able to pause & resume this timer and see its state modification,
• Be informed of the end of this timer,
• Stop this timer at any time and see its state modification.

Duration

1h30

USE COUNTDOWN HMI ELEMENT

In Sim4Sys-Designer

Create a new model TimerModel, with a Project TimerProject and a service TimerSystem.

In the State Machine:

• rename "FirstState" as "Initialized" (this is the starting state, where the countdown can be set up),
• add the state "Countdown_VB" (a specific state that may transmit the behavior of the countdown to VB).

You will need four requested flows:

• requests_start_countdown(value: Integer),
• requests_stop_countdown(),
• requests_pause_countdown(),
• requests_resume_countdown().

And four flows To ENV:

• starts_countdown(value: Integer),
• stops_countdown(),
• pauses_countdown(),
• resumes_countdown().

And one flow From ENV:

• countdown_ended().

In Standard Use, create four UseCases and five UserStories:

• Start a countdown
  • User starts a countdown
  
  • End of countdown
  
• Stop a countdown
  • User stops a countdown
  
• Put countdown in pause
  • User puts a countdown in pause
  
• Resume a countdown
  • Users resumes a countdown
  

In VB

Drag & drop a Countdown, put “Visibility” to hidden.

Create five controllers (see controllers overview, controllers management, and other controller dedicated pages) :

• Start countdown

  • Configure the controller :
    • Type of element : model
    • Model : select the model used
    • Event : Receive flow
    • Flow : starts_countdown
      
      
  
  
  
  • Set the sequence diagram :
    • Add a countdown lifeline
    • Add 2 actions :
      • Triggers : Start the countdown, select value as remaining time
      • Update parameters : Visibility to visible
        
        
  

• Stop countdown

  • Configure the controller :

    • Type of element : model
    • Model : select the model used
    • Event : Receive flow
    • Flow : stop_countdown

  • Set the sequence diagram :

    • Add a countdown lifeline
    • Add 2 actions :
      • Triggers : Stop the countdown
      • Update parameters : check Font color to red
        
        
    

• Pause countdown

  • Configure the controller :

    • Type of element : model
    • Model : select the model used
    • Event : Receive flow
    • Flow : pauses_countdown

  • Set the sequence diagram :

    • Add a countdown lifeline
    • Add 2 actions :
      • Triggers : Pause the countdown
      • Update parameters : check Font color to grey
        
        
  

• Resume countdown

  • Configure the controller :

    • Type of element : model
    • Model : select the model used
    • Event : Receive flow
    • Flow : resumes_countdown

  • Set the sequence diagram :

    • Add a countdown lifeline
    • Add 2 actions :
      • Triggers : “Resume the countdown”
      • Check Font color to black
        
        
  

• Countdown ended

  • Configure the controller :
    • Type of element : Scenario element
    • Basic element : Countdown
    • Event : Countdown ended
      
      
  
  
  
  • Set the sequence diagram :
    • Add a model lifeline (choose the model you use)
    • Add 1 action towards the model lifeline :
      • Flow : countdown_ended
        
        
  

Select the countdown element and apply the controllers you created :

In the timeline, add five “Timeline Actions” as triggers :

• Start countdown
• Pause countdown
• Resume countdown
• Start countdown 2
• Stop countdown

Then select each timeline action and in the behaviours tab create a triggered controller.

• Start countdown -> create the controller request to start countdown :
  • Add model lifeline
  • Add action towards the model lifeline with flow request_start_countdown, set value to 5

Apply the controller to your model instance :

• Pause countdown -> create the controller request to pause countdown
  • Add model lifeline
  • Add action towards the model lifeline with flow requests_pause_countdown

• Resume countdown -> create the controller request to resume countdown
  • Add model lifeline
  • Add action towards the model lifeline with flow requests_resume_countdown

• Start countdown 2

  • Select reuse controller and reuse the controller request to start countdown
    
    
  
  
  

• Stop countdown -> create the controller request to stop countdown

  • Add model lifeline
  • Add action towards the model lifeline with flow requests_stop_countdown
    
    
  
  
  

Run the simulation.

CREATE YOUR OWN TIMER INSIDE A MODEL

In Sim4Sys-Designer

Update the State Machine:

• add another State “Countdown_Model” (this state represents the logic and data model of the countdown),
• add two sub-states “Started” (the countdown is actively running) & “Paused”(the countdown is temporarily halted).

Add one flow From Engineer, to get Virtual Bench’s timestep:

• deltaT (value: Integer)

attention

The value getting from VB is in ms!

To convert this received value in seconds: add a Simulation Phase, a UseCase “Convert delta from ms to s” and a UserStory “Conversion” In the Sequence Diagram, add the Engineer Life Line, draw the Message “deltaT” from Engineer to TimerSystem (in State Initialized), then add an activity “convert()” an create a new Decimal variable named “deltaT_in_s”, copy/paste the followed code:

deltaT_in_s = deltaT_value/1000.0;

attention

Don’t forget the “.0” after “/1000”, overwise deltaT_in_s will be an Integer

You should have this Sequence Diagram at the end:

You will need four requested flows:

• requests_start_timer(value: Decimal)
• requests_stop_timer()
• requests_pause_timer()
• requests_resume_timer()

Four feedbacks:

• display_timer (value: Decimal)
• paused_timer()
• stopped_timer()

And one flow From ENV:

• clock()

In Standard Use, create four UseCases & six UserStories:

• Start a timer
  • User starts a timer
    • New Decimal variable named “timer”
    • Activity: register_timer_value()
      • Body: timer = requests_start_timer_value;
      
  • Decrementation of the timer
    • GC: timer > 0
    • Activity: decrease_timer()
      • Body: timer -= deltaT_in_s;
      
  • End of timer
    • GC: timer <= 0
    • Activity: reset_timer()
      • Body: timer = 0.0;
      
• Stop a timer
  • User stops a timer
    • Activity: reset_timer()
      • Body: timer = 0.0;
      
• Put timer in pause
  • User puts a timer in pause
  
• Resume a timer
  • Users resumes a timer
  

At the end, you should have this State Machine:

In VB

Drag & drop an Hour Display, put “Mode” to “Only seconds” & “Visibility” to hidden.

Create three controllers:

• display timer

  • Configure the controller :

    • Type of element : Model
    • Model : choose the model you use
    • Event : Receive flow with flow display_timer

  • Add Hour display element lifeline

  • Add action towards the Hour display lifeline

    • Check “Seconds” (not “Second”) & select the variable “value”
    • Set “Color” to #000000
    • Check “Visibility” and select visible
      
      
  

• pause timer

  • Configure the controller :

    • Type of element : Model
    • Model : choose the model you use
    • Event : Receive flow with flow paused_timer

  • Add Hour display element lifeline

  • Add action towards the Hour display lifeline

    • Set “Color” to #949494
      
      
  

• stop timer

  • Configure the controller :

    • Type of element : Model
    • Model : choose the model you use
    • Event : Receive flow with flow stopped_timer

  • Add Hour display element lifeline

  • Add action towards the Hour display lifeline

    • Check “Seconds” (not “Second”) & set it to 0
      • Set “Color” to #ff0000
        
        
  

Select the Hour display element and apply the controller you created :

In the timeline, add 5 “Timeline Actions” as triggers :

• Start timer
• Pause timer
• Resume timer
• Start timer 2
• Stop timer

For each timeline actions, create the corresponding trigger controller :

• Request to start timer :

  • Action send flow requests_start_timer to the model
  • Set the “value” to 5 (seconds)

• Request to pause timer :

  • Action send flow requests_pause_timer to the model

• Request to resume timer :

  • Action send flow requests_resume_timer to the model

• For the timeline action Start timer 2, reuse the controller Request to start timer

• Request to stop timer :

  • Action send flow requests_stop_timer to the model

You can finally run the simulation.