STEP-TAS Part 21 Format

Note

This page is unchanged from previous releases, and therefore shows the previous TASverterGUI.

The STEP-TAS protocol, and the STEP-TAS Part 21 file, are designed to handle geometry data, results data, and network data, but the current tools concentrate on converting a GMM into the geometry data or the TMM into the network data.

Therefore you will not be able to convert a GMM, or a STEP-TAS file of a GMM, into a TMM format. Similarly you cannot convert a TMM, or a STEP-TAS file of a TMM, into a GMM format.

Unfortunately, TASverter cannot determine in advance whether a STEP-TAS file represents a GMM or a TMM, and is likely give a traceback error if the STEP-TAS source file is the “wrong” format for the target conversion.

STEP-TAS Part 21 reader module

Activation of the Part 21 reader module

TASverter also offers the possibility of reading and writing files in the so-called STEP Part 21 format, formally defined in ISO 10303-21:2002. This is used as an “internal” format for TASverter.

The STEP Part 21 reader module can be activated from the command line using the option:

–from_TAS=STEPFile.stp

When the TASverter GUI is used the “Model Type” of the “From” file must be set to “STEP-TAS stp” (see figure below):

Activation of STEP-TAS Part 21 reader via the GUI

STEP Part 21 files contain a HEADER section. This section contains information about how the STEP file was generated and which schema was used to generate it. If the schema or version used is not compatible with the tas_arm EXPRESS schema used by TASverter, then TASverter will be unable to read the file and will give a fatal error. If the schema and version are compatible and the contents of the file adhere to the schema, then TASverter will attempt to read the entire file into memory.

While reading the STEP file, TASverter checks the validity of the entities that it encounters. It is able to detect, report and correct some types of errors, and will continue to read the file. However, processing will stop as soon as TASverter encounters a fatal error while reading the STEP file.

STEP-TAS Part 21 writer module

Activation of the Part21 writer module

The STEP Part 21 writer module can be activated from the command line using the option:

–to_TAS=STEPFile.stp

When the TASverter GUI is used the “Model Type” of the “To” file must be set to “STEP-TAS stp” (see figure below)

Activation of STEP-TAS Part 21 writer via the GUI

The STEP Part 21 writer module generates a text file formatted as defined in ISO 10303:21-2002. Its contents can then be read by TASverter or by any other tool able to read STEP files based on the tas_arm EXPRESS schema.