@Joe Riel 

delay_trial.msim

hello !

i send the problematic file!

thank.

@Joe Riel 

hello,

i tested this circuit , without problem !

with Fixed Euler solver.

and uper limit at 0.5 for the real to logic converter.

I think that a problem occur for logic variable for the function delay in the model Transport Delay component:

model Modelica.Electrical.Digital.Delay.TransportDelay "Transport delay with initial parameter"
    Modelica.Electrical.Digital.Interfaces.DigitalInput x(start = Modelica.Electrical.Digital.Interfaces.Logic.'U', fixed = true) "Connector of Digital input signal";
    Modelica.Electrical.Digital.Interfaces.DigitalOutput y "Connector of Digital output signal";
    parameter Modelica.SIunits.Time delayTime(start = 0) "delay time";
    parameter Modelica.Electrical.Digital.Interfaces.Logic y0 = Modelica.Electrical.Digital.Interfaces.Logic.'U' "initial value of output";
protected
    Modelica.Electrical.Digital.Interfaces.Logic x_delayed;
equation
    y = if 0 < delayTime then if delayTime <= time then x_delayed else y0 else pre(x);
    x_delayed = integer(delay(x, delayTime));
end Modelica.Electrical.Digital.Delay.TransportDelay;

compared to Fixed Delay component:

block Modelica.Blocks.Nonlinear.FixedDelay "Delay block with fixed DelayTime"
    Modelica.Blocks.Interfaces.RealInput u "Connector of Real input signal";
    Modelica.Blocks.Interfaces.RealOutput y "Connector of Real output signal";
    parameter Modelica.SIunits.Time delayTime(start = 1) "Delay time of output with respect to input signal";
equation
    y = delay(u, delayTime);
end Modelica.Blocks.Nonlinear.FixedDelay;

thank for your help !!

@Joe Riel 

wanting to simulate RS gate, I think the source of the trouble is in the following component:

modelica model extract:

model Main
   import Modelica.Constants.inf;
   import Pi=Modelica.Constants.pi;
   import pi=Modelica.Constants.pi;

   public Modelica.Electrical.Digital.Delay.TransportDelay TD1(delayTime=0.1e-1, y0=Modelica.Electrical.Digital.Interfaces.Logic.'U');
   public Maplesoft.Electrical.Digital.Sources.Clock C1(w=50, T=1, T0=0);
equation
   connect(C1.y, TD1.x);
end Main;