Advanced ABS Options dialog box

The Advanced ABS Options dialog box is opened when you click on the Advanced button in the Adaptive Sweep Settings section of the Analysis Options dialog box. The controls are detailed below.

ABS Caching Level: The ABS caching level determines if and how much of the ABS caching data is stored in your project. The levels are detailed below.

• None: Select this option if you do not wish to store any ABS cache data in your project. If this option is selected and you stop an ABS analysis before completion, the only data available is the data calculated for the discrete data points. When you resubmit the ABS job, the cache data will need to be recalculated. Thus, the analysis must start all over again.

• Stop/Restart: Select this option to store the ABS cache data while an ABS analysis is running. This allows you to stop an ABS analysis and restart it at a later time without losing the data from the processing done before the stop. This option deletes the cache data when convergence is reached and the ABS analysis is completed. This is the default setting.
• Multi-Sweep plus Stop/Restart: Selecting this cache level saves the ABS cache data for every analysis performed on the project. This saves you processing time on any subsequent ABS analyses but be aware that the cache data will be calculated for any analysis of the project including non-ABS types of analysis, increasing the project size. This option should be used when you think you might want to re-analyze the project using different ABS ranges or settings.

It is important when using this option that all your analyses use the same subsectioning frequency. This ensures that any pre-existing ABS cache data can be used in the present analysis. The default setting used to determine the subsectioning frequency is to use the highest frequency from the present analysis job. If you perform multiple sweeps over different frequency bands then the cache data from one run will be invalid for the next, since the subsectioning frequency would be different. In order to avoid this you should use the controls for the subsectioning frequency found in the Advanced Subsectioning dialog box to ensure that the same frequency is used for all analyses. For more details about setting the subsectioning frequency, please see the Advanced Subsectioning Options dialog box.

ABS Frequency Resolution per Sweep: The resolution provides the minimum value of the gap between data points in an ABS sweep. This can be calculated automatically by the solver or input by the user.

• Automatic: The resolution of the frequency band used in an ABS analysis is determined by the analysis engine, em. This is the default setting. The automatic setting provides approximately 300 frequency points in the band.
• Manual: If you wish to set the resolution for an ABS analysis, select this radio button and enter the desired resolution in the adjacent text entry box. The units for this value are the presently selected frequency units for the project.

There are several things to be aware of when using the manual setting for the ABS resolution. Coarse resolution does not speed things up. Once a rational polynomial is found to "fit" the solution, calculating the adaptive data uses very little processing time. A really coarse resolution could produce bad results by not allowing the ABS algorithm to analyze at the needed discrete frequencies. Fine resolution does not slow down the analysis unless the number of frequency points in the band is above approximately 1000 - 3000 points. A step size resulting in at least 50 points and less than 2000 points is recommended.

Enhanced Resonance Detection: For details on this option, please see the Advanced Options Dialog Box .