We have an old optical burn table for cutting steel plate, for which we need to print out hardcopy burn patterns. We typically do this from model space, drawing a border around the patterns to make using "Plot Window" a little more convenient. Typically I put a text note with the paper size in the corner, so the user doesn't need to measure the border every time to figure out the paper size.
I've been working on a block to automate part of this process. It uses a dynamic block with an adjustable "LENGTH" parameter. This parameter is then included as a field in an attribute that replaces the manual text note. In theory, this should always show the paper size. However, the field doesn't update automatically (during REGEN, SAVE, etc.) when the block is used in model space. Instead, it has to be manually updated using "Update Fields." I'm fairly new to fields in AutoCAD, so I'm not sure where things are going awry.
As a test, I put it in paper space, and verified that it does update properly there. However, the procedure where this block is used is typically performed in model space. Is there a way to get the fields to update in model space the same way they do in paper space, or am I just stuck with a manual update?
Example file containing the block is attached. Thanks in advance for any help you can provide.