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How to use and/or create a Timer

PRESENTATION​

Prerequisites​

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
    User_starts_a_countdown
    • End of countdown
    End_of_countdown
  • Stop a countdown
    • User stops a countdown
    User_stops_a_countdown
  • Put countdown in pause
    • User puts a countdown in pause
    User_puts_a_countdown_in_pause
  • Resume a countdown
    • Users resumes a countdown
    User_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

    start_countdown_controller_configuration

    • 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

    Start_countdown_controller_sequence

  • 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

      Stop_countdown_controller_sequence

  • 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

    Pause_countdown_controller_sequence

  • 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

    Resume_countdown_controller_sequence

  • Countdown ended

    • Configure the controller :
      • Type of element : Scenario element
      • Basic element : Countdown
      • Event : Countdown ended

    countdown_ended_controller_configuration

    • Set the sequence diagram :
      • Add a model lifeline (choose the model you use)
      • Add 1 action towards the model lifeline :
        • Flow : countdown_ended

    coutdown_ended_controller_sequence

Select the countdown element and apply the controllers you created :

Countdown_controller_application

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

  • Start countdown
  • Pause countdown
  • Resume countdown
  • Start countdown 2
  • Stop countdown
timeline_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
Start_countdown_timeline_controller

Apply the controller to your model instance :

Start_countdown_timeline_controller_application

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

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

  • Start countdown 2

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

    Start_countdown_2_timeline_controller_reuse

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

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

    Stop_countdown_timeline_controller

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)
caution

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;
caution

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

You should have this Sequence Diagram at the end:

Conversion

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;
        User_starts_a_timer
    • Decrementation of the timer
      • GC: timer > 0
      • Activity: decrease_timer()
        • Body: timer -= deltaT_in_s;
        Decrementation_of_the_timer
    • End of timer
      • GC: timer <= 0
      • Activity: reset_timer()
        • Body: timer = 0.0;
        End_of_timer
  • Stop a timer
    • User stops a timer
      • Activity: reset_timer()
        • Body: timer = 0.0;
        User_stops_a_timer
  • Put timer in pause
    • User puts a timer in pause
    User_puts_timer_in_pause
  • Resume a timer
    • Users resumes a timer
    User_resumes_a_timer

At the end, you should have this State Machine:

SM

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

    controller_display_timer

  • 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

    controller_paused_timer

  • 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

    controller_stopped_timer

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

hour_display_controller_application

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

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

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.