id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
3730	Wrong reference files for Modelica_Synchronous	Rüdiger Franke	Adrian Pop	"Some of the remaining verification failures are due to wrong reference files. In particular the models that start to tick after initial simulation time:

Modelica_Synchronous.Examples.Elementary.BooleanSignals.BackSample
Modelica_Synchronous.Examples.Elementary.IntegerSignals.Hold
Modelica_Synchronous.Examples.Elementary.RealSignals.BackSample
Modelica_Synchronous.Examples.Elementary.RealSignals.Hold

Take the latter as example. See:
https://test.openmodelica.org/libraries/Modelica_Synchronous_cpp/files/Modelica_Synchronous.Examples.Elementary.RealSignals.Hold.diff.shiftSample.y.html

The reference has the initial value of 0 for shiftSample.y (with the alias hold.u). The Cpp runtime produces -1. This is y_start of the connected hold model. The model explicitly states: `hold.u(final start=y_start)`.

The Modelica spec states in a similar case for accessing a not yet calculated value: **""The operator previous(xd) returns the value of xd at the previous clock tick. At the first sample instant, the start value of xd is returned.""**"	defect	closed	high	Future	Testing Framework	v1.9.4-dev-nightly	fixed		Bernhard Thiele Lennart Ochel