It allows to choose between three different options:

• every n time step : means that every n time step a complete result field will be written in the file having the extension ".rdt". For large mesh, choosing a too small number n (positive integer) may induce very large files and is also quite costly in terms of CPU time.
• every x seconds : means that every x seconds a complete result field will be written in the file having the extension ".rdt". Again a too small value x (with respect to the duration of the transient to be simulated), may induce a large number of intermediate fields (especially with the automatic time step), since interpolated fields may be generated when x is smaller than the time step used.
• time list : corresponds to a list of instants (given in seconds - for exemple two hours and 10 hours should be indicated 7200 36000) for which complete result fields will be written in a result file having the extension ".rdt"