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Can I import a STEP file from my CAD system?Why can't I read my old STEP-TAS file?Can I use the STEP-TAS files to exchange models?Can I use the STEP-TAS files for long term archive?Can I convert my STEP-TAS files if the protocol changes again?Does TASverter handle cutting operations?What happened to the cutting operations in my geometry?
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TASverter: Frequently asked questions
 
Why can't I get TASverter to run at all?
 
One of the folders or directories on the path to TASverter probably contains a space or other special character in its name. This is a common problem on Windows if you have installed in the "Program Files" or somewhere under the "Documents and Settings" folders.

Reinstall somewhere else, e.g. C:\TASverter and try again.  
 
Can I import a STEP file from my CAD system?
 
No, you will not be able to import a CAD STEP file into TASverter.

The word "STEP" is used informally to refer to a range of data exchange protocols that encompass a wide variety of different application domains. CAD systems typically use one of two particular application protocols, AP203 and AP214. STEP-TAS is a completely different application protocol, written specifically for Thermal Analysis for Space. STEP-TAS uses some of the same lower-level building blocks that the AP203 and AP214 protocols use, such as the Part21 text encoding. However, the actual meaning of the content within that format is determined by the protocol that was used to write the file. The STEP file produced by a CAD system is a Part21 file that can only be imported into a system that understands the AP203 or AP214 protocol. The STEP-TAS file produced by TASverter is a Part21 file that can only be imported into a system that understands the STEP-TAS protocol.
 
 
Why can't I read my old STEP-TAS file?
 
Several tool vendors provided a prototype interface to an early version of the STEP-TAS protocol that was available in 1998. The experience of using the protocol and the interfaces resulted in a far better understanding of the complexity of issues involved in data exchange. As a consequence, the STEP-TAS protocol has been extensively redesigned since 1998 to simplify these interfaces and address these issues.

Similarly, implementing new features since TASverter-r2005-06-10 has lead to some additions and improvements to the protocol.

Unfortunately this means that the STEP-TAS files written using the export function provided by some versions of ESARAD, THERMICA and Thermal Desktop, and by older versions of TASverter, are not compatible with the current STEP-TAS protocol.

If you do not have the original native tool format version of the model in your old STEP-TAS file, there is a small possibility that you might still be able to recover the model from the old STEP-TAS file, but this is not guaranteed. You could try importing your old STEP-TAS file using the same version of the tool that was used to export it, saving the model in one of the native tool formats, and then using the latest version of TASverter to convert the native tool format.
 
 
Can I use the STEP-TAS files to exchange models?
 
In the short term there is the restriction that the recipient must have a "reader" that is compatible with the version of the STEP-TAS protocol that you are using. The easiest way of ensuring this would be for the recipient to down-load the same version of TASverter as you are using. If you are developing your own STEP-TAS "reader" or "writer" interfaces then you may have a problem.
 
 
Can I use the STEP-TAS files for long term archive?
 
This is the ultimate goal of the STEP-TAS development. ESA is working to formalise STEP-TAS under ISO TC184/SC4. Once this is done, the protocol will become a real standard and will be frozen.

Lessons learned from the past have been brought to good use (see Why can't I read my old STEP-TAS file?) and the STEP-TAS protocol has undergone major changes since the early releases. The STEP-TAS protocol *should* now have reached stability for those parts of the protocol needed by the currently implemented "readers" and "writers". While every effort will be made to maintain backwards compatibility from this version onwards, it is possible that incorporating additional "readers" and "writers" for new tools may highlight the need for changes. Therefore, until the protocol is completely frozen, users should be aware that a STEP-TAS file written now is not guaranteed to be suitable for long term archival of model data. The user is advised to retain a copy of the model in the native format of the thermal tool in addition to the STEP-TAS file. It should always be possible to re-convert the native format using a more up-to-date of a conversion tool such as TASverter.
 
 
Can I convert my STEP-TAS files if the protocol changes again?
 
As mentioned above, STEP-TAS files written using the old prototype interfaces and early versions of the STEP-TAS protocol are no longer supported.

The STEP-TAS protocol used in TASverter version r2007-03-19 has been revised to both simplify the protocol based on the experience of converting real world models using commercial analysis tools, and to extend the protocol to allow the implementation of additional conformance classes and new features. It is hoped that these changes address almost all of the future requirements of STEP-TAS and TASverter so that they can support a wider range of tools and models. However, experience has shown that "the devil is in the details" and full confidence in the new parts of the protocol can only be achieved by using the protocol to implement the "readers" and "writers" for several commercial tools that require those features.

One important change to the protocol, starting with TASverter version r2005-06-10, is the addition of information that describes which version of the STEP-TAS protocol was used to create the STEP-TAS file. If any further changes are needed to the protocol and the Part21 files, the highest priority will be given to backwards-compatibility, and where this fails, to provide a specific version-to-version upgrade utility if possible. However, until the protocol has survived its "trial by fire" in the actual implementation of the new "readers" and "writers", this can only be a goal and not a promise. So users are advised to keep a copy of the model in native format as well, as mentioned in the previous item.
 
 
Does TASverter handle cutting operations?
 
The short answer? Yes. This release sees the introduction of cutting surfaces to STEP-TAS and therefore sees TASverter promoted from conformance class CC1 to CC3. So TASverter is now able to represent cutting operations in the internal STEP-TAS representation of an input model.

And the long answer? See the next item.
 
 
What happened to the cutting operations in my geometry?
 
If your input geometry contains cutting operations, TASverter is now able to represent these operations in the internal STEP-TAS representation of an input model. However, TASverter only "records" the cutting operations, it does not "evaluate" or "convert" the cutting operations. What happens when this internal representation is output depends on the target tool format. If the target tool is able to handle cutting operations, then the internal representation will appear as cutting operations in the output. If the target tool does not handle cutting operations TASverter outputs the cutting operation with the geometry primitive being cut as a normal primitive, but how the cutting primitive is output depends on the tool. For example, converting an ESARAD geometry containing a cutting operation to THERMICA will produce the cutting primitive in a comment, whereas converting to a PATRAN ses file will produce a normal geometrical shape for the cutting primitive.

If you were expecting "holes" when you visualise the THERMICA SYSBAS file output by TASverter and these don't appear, then you should check for a comment containing the cutting primitive. Similarly, if the PATRAN ses file output by TASverter contains some additional shapes, you should verify whether these correspond to the cutting primitive. In both cases, TASverter has provided as much information about the cutting primitive as possible and it is now up to you to work out how to achieve the equivalent geometry without using a cutting operation.
 
 
Last update: 16 April 2007

 


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STEP-TAS technical detailsTASverter: Release notesTASverter: Installation notesTASverter: Download page
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