Changes
</table>
Before you run your first FDTD simulation in [[EM.Tempo]], let’s take a closer look at the FDTD simulation engine’s settings. Click the {{key|Settings}} button next to the “Select Engine” drop-down list to bring up the FDTD Engine Settings dialog. The “Convergence” convergence section ("Termination Criterion") of this dialog offers three criteria for terminating the FDTD time marching scheme. The first one is a <b>Power Threshold</b>, which normally has a default value of -30dB. The second one is a <b>Maximum Number of Time Steps</b>, which normally has a default value of 10,000. The third option is labeled “Both”, which means that both of the above termination criteria will be considered until one of them is met. For this particular structure, the wizard set the power threshold equal to -50dB and the maximum number of time steps to 20,000.
{{Note|For highly resonant structures, it is recommended that you establish a much more demanding convergence criterion with a lower power threshold value and a larger number of time steps.}}
