export of dymola model requires the derivative of its input
input,modelica,derivative,dymola,openmodelica
Typically, this happens when the input signal feeds directly into a quantity that must be continuous (e.g., where a discontinuity would cause an impulse). The way I deal with this situations is to put a high gain first order filter on the input. This ensures that the actual signal is...
OpenOPC tag activation?
I've been able to find a workaround by using the properties method of OpenOPC. The value and quality return by the method properties are not consistent with the read method. It seems that the properties method return the right value (with good quality) whereas the read method does not....
DASSL solver in OpenModelica and Dymola
The DASSL solvers are different. OpenModelica has a variety of different DASSL solvers, so even OpenModelica is different from itself. The OpenModelica dassl code is based on daskr (previously, it was ddasl). Options include things like: dasslJacobian=[coloredNumerical (default)|numerical|internalNumerical|coloredSymbolical|symbolical] dasslnoRootFinding dasslnoRestart maxStepSize maxIntegrationOrder Event handling is done separate to the numerical...
time derivative of a variable as a signal and not as a function
Modelica.Blocks.Continuous.Derivative x_dot(start=1) This provides an approximation of the derivative. I gave the x as an input and got x_dot.y as the derivative with no problems.
How can I do auto-completion of text in Dymola?
In the editor, start typing then hit Ctrl + space. I don't know about the command prompt. /Rene...
Modelica encoding problems
utf-8,character-encoding,modelica,dymola,openmodelica
Testing UTF-8 in latest Dymola (Linux), it seems as if Dymola does not change the encoding to ISO-8859-1 any longer (to my memory it used to change this). It does however, not look good since it is displayed as if the UTF-8 text is ISO. The easiest way to get...
Dymola - Continuous Input for State Machine
state,continuous,modelica,dymola
Well the issue there is the inferred clock that you have to explicit, otherwise you are using a continous signal (sine.y) in a discrete state machine that has its own discrete clock. To sample the sin signal with the clock of the state machine, a sample block is enough: model...