Delimiter for DMXChannel Allows Non-Unique Channel Names

[Firionus]

Problem

The following clash of DMXChannel names is not prohibited by the GDTF standard:

• DMXChannel 1: "a_b_c" (Geometry "a_b", Attribute "c")
• DMXChannel 2: "a_b_c" (Geometry "a", Attribute "b_c")

This is because the Name Type allows underscores, which are also used as a delimiter between Geometry and Attribute for the name of the DMXChannel.

Proposed Solution

Require in the standard that DMXChannel Names as computed from Geometry and Attribute of the first Logical Channel must be unique.

Alternative Solutions

• Disallow underscores (U+005F) in the Name Type. This has the disadvantage of breaking existing Attribute Definitions like CIE_X, ColorRGB_Red, etc.
• Change the Delimiter for the Channel Name to one of the characters that are already disallowed, which are ! $ . & , ? [ \ ] ^ { | } ~ ␡.

[nicavolites]

Personally I would prefer the proposed solution or changing the Geometry name to a different type that has does not permit underscore. The alternative solutions will impact parsing.

[moritzstaffel]

I think the proposed version is good.

I think we never made it clear in the Spec that we assume this. Have have added this in the new proposal for the spec.

here is the proposed change on the Spec text.

Note that you can get the full spect text here: https://www.beuth.de/de/technische-regel/din-spec-15800/324748671 That is currently the only place where you find the full spec online.

[nicavolites]

Looks good to me. As a minor point I think 'consists' should be 'consist'.