Missing definition of 'page connector pair ID' match mechanism in case of multiple SequenceOnPage/OffPage connectors between two (or more) pages

[Erik0x42]

As of AML library v0.0.10, a scenario with two pages (A and B), with two SequenceOffPage on page A and two corresponding SequenceOnPage on page B will lack enough digitized machine readable information to make unambiguous matches of the intended pairs of connectors.

In the README.md at a1b2d24 there are screenshots (at the very end of the README) showing from/to step names in the visual representation of the off page connectors, and this information is required in the digitized AML representation to establish 'fully qualified' cross references when combined with the DrawingReference attribute.

My proposal is to add an attribute named 'ElementRef' to both SequenceOnPage and SequenceOffPage types, and that the README is updated to require this ElementRef to be filled with the AML Name (from InternalElement header) of the element being referenced/connected by the respective SequenceOnPage/OffPage connectors.

[AlexTxen]

Same approach is intended for SequenceOnPage/SequenceOffPage, as used for SignalOnPage/SignalOffPage representing off-page connectors on SCD's. SignalOnPage/SignalOffPage also don't have specific attribute for reference unique number/ID and AML node name is used for this purpose. Therefore Name of SequenceOnPage/SequenceOffPage AML node is unique reference number/ID.

[Erik0x42]

There must be recognizable information between the visual (PDF) representation, and the digitized machine readable representation. When you say "same approach", do you mean to say

• that the page connector shapes from SCDs - which includes the vertically oriented "Unique signal reference identifying the signal connection" (we like to call it 'Uniref') - should replace the currently shown shape for SFC page connectors?
• or, that the current shape should be updated to show this unique reference number, in addition to the document number and the source/target element name typically shown on the second line?

I would be skeptical to having one matching mechanism for machine readability and a different matching mechanism for human readability. This would reduce robustness against human error, and make troubleshooting more 'expensive' than necessary.

And regardless of what we conclude and agree on, the mechanism for matching the correct pair of SequenceOff/OnPage must be documented clearly in this repository.

[Erik0x42]

I would also argue that the string value from the second line in the current SFC page connector shape is in need of being encoded into AML, regardless of whether it is a free text/description field, or a rule governed part of an identifying 'key' (ie, the line where you have the value "DESC" in your screenshot).

Otherwise the AML transfer will be lossy.

[Erik0x42]

Title changed to better reflect agreed action in workshop 2023-06-21.

[cdenisey]

Discussions have been taken in the workshop held on 21.06.2023, refer to item 11. https://github.com/equinor/iec63131/blob/2c8fa87426e072459c5afc61afd97b1ce53cd28c/MOM%20AML%20Library%200.0.11%20workshop.docx

It has been agreed to add Unique ID to the sequence On / Off page connectors.

[AlexTxen]

No change to library (Unique ID will form name of page connector AML instance node during export). Documentation is to be updated. Issue can be closed after documentation update.