Integrator output changes while input is zero

Hi everyone,

I have a problem with my model (see attached). As the title says, at one point the output of an integrator block changes although the input is zero. You will find the according integrator block (blue one) in the subsystem 'Differential'. Scope2 shows the output of the intergrator block. When zooming in you will realize, that the signal changes for t > 22 seconds although the input (Scope1) is zero during the same period of time. This fact causes the simulation to slow down from that point on.

Maybe anyone has had that problem before. Thanks a lot in advance! Michael

PS: If you would like to start the simulation, run the script before

[John D'Errico]

Are you positive that it is IDENTICALLY zero? Or is it just fairly small, and it looks like zero?

[Michael Korherr]

Hi John,

I checked that by means of a logic operator (compare to zero) and it gives me logical 1 for t > 22 seconds. Should therefore be identically zero.