MATLAB: Is it possible log an undefined amount of data with an xPC Target File Scope

file scopenumsamplesxpc targetxpc target file scopexPC TargetBox

In Simulink, a Scope or a To File block will log a data point at every time step (or at the specified sample time) from starting a simulation to stopping it (or until MatLab runs out of memory but I've never know that happen even with large simulations).
However, with xPC Target File Scopes you have to specify the number of data points you would like to log. I would like to log a data point at every time step (or a sample time as specified by myself) from starting a simulation to stopping it.
Is this possible or, for every simulation I perform, do I need to calculate how many data points I need to log?
Considering my step time is 1ms, the default 250 samples would not get me very far!

Best Answer

  • You do not need to know how many points you will need to log. The number of samples (default 250, as you note) is most relevant for triggering: 250 contiguous samples will be logged after each trigger. If you are not using triggering, you can leave it at 250 or increase to some value such as 1000 (this helps act as a buffer in case the file writing falls behind momentarily).