# DA Card

This card controls the export of data to additional ASCII files. For example the currents can be exported to the .out file or S-parameters can be exported to a Touchstone file.

On the Request tab, in the Output control group, click the  Data output (DA) icon.

The card allows to switch the export of data on or off. It only affects those cards that follow the DA card, such as the SP card for S-parameters. By default no such export files are created. The .out file is always created and the DA card is set, by default, to write all results to this file.
Warning: For large datasets (such as surface currents at many frequency points) the .out file can become very large. The output of these results can then be deactivated with the DA card.

In order to display results in POSTFEKO only the binary output file (.bof file) is required. If the output of results to the .out file was deactivated, a header will still be written to this file to identify the type of computations that were requested.

## Parameters:

Write electric fields to
The electric fields can be exported to a .efe file. The output of this result type to the .out file can also be activated/deactivated.
Write magnetic fields to
The magnetic fields can be exported to a .hfe file. The output of this result type to the .out file can also be activated/deactivated.
Write far fields to
The far fields can be exported to a .ffe file. The output of this result type to the .out file can also be activated/deactivated.
Write currents/charges to
The currents can be exported to a .os/ol file. The output of this result type to the .out file can also be activated/deactivated.
Write residue of iterative solution to *.cgm file
The residue of the iterative algorithm used to solve the matrix equation is stored in a .cgm file.
Write EM losses to *.epl file for thermal analysis
An element power loss .epl file is exported which contains the electromagnetic losses for each element in the model. The .epl file can be used in other thermal simulations with the NASTRAN .nas file and label mapping .map file.
Write S-parameters to Touchstone *.snp file
The S-parameters (SP card) are written to a file in Touchstone .snp format (v1.0). For each configuration containing an S-parameter data request, a separate Touchstone file is created. The file name will be of the form <FEKO_base_filename>_<requestname>(k).snp where n is the number of ports and k is an integer counter. The counter (k) is added to distinguish between the results of multiple requests with the same name and the same number of ports. For a one-port request without an SP card, the name of the AX card (source) is used.
Write spherical wave expansion to TICRA *.sph file
A spherical wave expansion of the far field as computed by Feko is exported to an SWE file (extension .sph) which can be imported into GRASP from TICRA (code for reflector antenna modelling).
Note: The FF card must follow the DA card with spherical mode coefficients requested in the FF card.
Write near fields to SEMCAD *.dat file
The near fields can be exported to a SEMCAD .dat file. The output of this result type to the SEMCAD .dat file can be activated/deactivated.
Write near fields in tetrahedral mesh to SPARK3D *.fse file
The near fields calculated at the vertices and edge mid-points inside a tetrahedral mesh can be exported to a .fse file. The output of the result type to the .fse file can activated/deactivated.
Write error estimates to the *.out file
The error estimates can be exported to the .out file.
Write generalised S-parameter matrix to FEST3D *.chr file
The generalised S-parameter matrix (GSM) for waveguide ports are exported to a FEST3D .chr file.
Write transmission / reflection coefficients to *.tr file
The transmission and reflection coefficients can be exported to a .tr file.
More than one DA card is allowed in one input file. Therefore using the following sequence of control cards, with the appropriate options, will cause only specific blocks of the same data type to be exported to the data file.
DA ... ** Write near fields activated
FE ...
DA ... ** Write near fields deactivated
FE ...

With this sequence, the electric fields calculated with the first FE card can be written to the .efe

file, but not those of the second FE card.