Create Delay with C-script

Question

Dear Oliver,

I am a new PLECS user. Attached is the model to create a delay that you created before.

Could you please explain the below commands in detail? I am very new to PLECS C-script, so I don't understand your command.

Your help is greatly appreciated!

Regards,

Alex

if(IsMajorStep)

{

if(IsSampleHit(0))

{

if(Input_pre == 0 && InputSignal(0, 0) == 1)

{

double nextHit = CurrentTime + InputSignal(1, 0);

if (nextHit > CurrentTime)

NextSampleHit = CurrentTime + InputSignal(1, 0);

else

OutputSignal(0, 0) = 1;

}

if(Input_pre == 1 && InputSignal(0, 0) == 0)

{

OutputSignal(0, 0) = 0;

}

}

if(IsSampleHit(1))

{

NextSampleHit = NEVER;

OutputSignal(0, 0) = 1;

}

}

Answer 1

You should read the chapters "How PLECS works" and "Using C-Scripts" in the PLECS manual. I put some comments in the code (and made some additions) below to make it more understandable.

// We are not worried about integration and such, so only consider major steps

if(IsMajorStep)
{

   // Continuous task: Rising edge detection and start of delay
   if(IsSampleHit(0))
   {      

      // Detect edge of incoming signal
      if(Input_pre == 0 && InputSignal(0, 0) == 1)
      {

          // Calculate time or next execution of task 1
          double nextHit = CurrentTime + InputSignal(1, 0);
          if (nextHit > CurrentTime)
             NextSampleHit = CurrentTime + InputSignal(1, 0);
          else
             OutputSignal(0, 0) = 1; // no delay, output 1 immediately
      }

      // Detect falling edge
      if(Input_pre == 1 && InputSignal(0, 0) == 0)
      {

         // Cancel delay

         NextSampleHit = NEVER;

         // Output 0 immediately
         OutputSignal(0, 0) = 0;
      }
   }

   // Task 1: executed after specified delay after edge detection
   if(IsSampleHit(1))
   {

      // Safety measure: check if input signal is still 1

      if (InputSignal(0, 0) == 1)
         OutputSignal(0, 0) = 1; // turn-on delay over, turn on signal
   }
}

Kind regards,

Oliver

 

Comments

Thank you, Oliver. I really appreciate your help!