This information is part of the Modelica Standard Library maintained by the Modelica Association.

The Boolean output y is a signal defined by parameter vector table. In the vector time points are stored. The table interpolation has the following properties:

• At every time point, the output y changes its value to the negated value of the previous one.
• Values outside of the table range, are computed by extrapolation according to the setting of parameter extrapolation:

  extrapolation = 1: Hold the startValue or last value of the table,
                     if outside of the table scope.
                = 2: Extrapolate by using the derivative at the first/last table
                     points if outside of the table scope.
                     (This setting is not suitable and triggers an assert.)
                = 3: Periodically repeat the table data (periodical function).
                = 4: No extrapolation, i.e. extrapolation triggers an error
  

• Via parameter shiftTime the curve defined by the table can be shifted in time. The time instants stored in the table are therefore relative to shiftTime.
• If time < startTime, no interpolation is performed and false is used as ordinate value for the output.

The precise semantics is:

if size(table,1) == 0 then
   y = startValue;
else
   //            time < table[1]: y = startValue
   // table[1] ≤ time < table[2]: y = not startValue
   // table[2] ≤ time < table[3]: y = startValue
   // table[3] ≤ time < table[4]: y = not startValue
   // ...
end if;