STEP files creation - Inventor 2021 vs Inventor 2016 - differences inside STEP files

[kmcga]

Dear Community,

I use STEP files (AP214 protocol) created by Inventor to create assembly instructions in 3rd party software (SW Composer).

Previoulsy I worked with Inventor 2016 but this year I had upgrade to Inventor 2021.

The problem is that I can perform automatic update of assembly instructions created based on STEPs from Inventor 2016 with STEP created by Inventor 2016 but STEPs from Inventor 2021 does not work - no change in assy instruction.

Obviously I can update assy instruction created from Inventor 2021's STEP file with STEP coming from Inventor 2021.

When I am opening both STEP files in Notepad I see differences in characteristics like PRODUCT and PRODUCT_DEFINITION - please review attachment STEP_files_differences. Also display names in Composer are different but I think this is connected with mentioned characteristics - attachment STEP_files_inconsistency.

Is there any way to standarize STEP files created by Inventor and use the "new" STEP files to update "old" assy instructions? How can I adapt STEP files from Inventor 2021 to previous "layout"?

Currently I use Inventor 2021.1.2 but there is no difference in Inventor 2021.3 - I tested it as well.

I would be grateful for quick answer and hints.

Best regards

Krzysztof

[johnsonshiue]

Hi! The behavior does not make sense to me. I sounds like a bug to me. Please share the STEP files here. I would like to understand it better.

Many thanks!

[kmcga]

Hi Johnson,

thank you for your prompt reply. I had to find some non-confidential STEP files. Attached you can find them.

Best regards

Krzysztof

[johnsonshiue]

Hi Krzysztof,

The difference may be an intended change. Interestingly, if I import the two STEP files to Inventor 2021, I am not seeing any difference. I will need to work with the project team to understand the behavior better.

Many thanks!

[kmcga]

Hi Johnson,

true, there is no impact for displaying in Inventor but it has huge impact for 3rd party software - update of assembly instructions is impossible.

I look forward to hearing from you.

Thank you in advance.

Krzysztof

[johnsonshiue]

Hi Krzysztof,

I have contacted the project team and got some update on this issue. There was indeed a behavioral change in categorization based on STEP community's best PDM practice. Here is the reference https://www.cax-if.org/documents/pdmug_release4_3.pdf.

The product_definition is defined as the following:
ENTITY product_definition
SUPERTYPE OF (ONEOF(composite_assembly_sequence_definition, laminate_table, ply_laminate_sequence_definition));
id : identifier;
description : OPTIONAL text;
formation : product_definition_formation;
frame_of_reference : product_definition_context;
DERIVE
name : label := get_name_value(SELF);
WHERE
WR1:
SIZEOF(USEDIN(SELF, 'STEP_MERGED_AP_SCHEMA.NAME_ATTRIBUTE.NAMED_ITEM')) <= 1;
END_ENTITY;

Before the change, both the "id" and the "description" were the product names. After the change, the "id" is the product id defined by Inventor for the product but the "description" stays the same. Inventor2021 is correct according to the recommended practices in the community.

If you would like the project team to take a further look, please feel free to share the Inventor files with me directly johnson.shiue@autodesk.com. I am more than happy to work with the project team to understand the issue better.

Many thanks!