Importing diagrams and custom symbols
Bringing an existing diagram in as a background to draw over, and tracing your own image into a vector symbol that exports to CAD as real geometry.
Diagram mode takes two kinds of import, and they behave differently on purpose. An existing single-line diagram — SLD — comes in as a background picture you draw over. An image of a symbol comes in as a vector symbol you can place like any other. Knowing which is which saves a wasted afternoon: the first cannot be edited, the second can.
| What you import | What you get | Editable |
|---|---|---|
| An existing diagram, with 📄 Import PDF / DXF | A high-resolution picture placed behind the sheet | No — only what you draw on top of it |
| An image of a symbol, with 🖼 Import Image Symbol | A vector symbol added to your palette | Yes — it is a symbol like any other |
Importing an existing diagram
📄 Import PDF / DXF brings a diagram you already have onto the sheet. The first page of the file is drawn to a high-resolution image, and that image is placed as a background on the drawing sheet. You then overlay editable symbols, wires and text on top of it, and the whole thing — background and overlay together — carries into the exported PDF report.
- What it shows
- The sheet with an imported diagram behind it and at least one editable symbol and wire placed on top, so the difference between background and editable content is visible.
- How to get there
- In diagram mode, import a diagram file, then place one symbol and one wire over it.
- Callouts to add
- Label the background and the editable symbol.
Why it comes in as a picture
A vector diagram cannot be reliably read back into typed equipment symbols. What a drawing file contains is lines, arcs and text; what it does not contain is any record of which lines were a circuit breaker, which were a current transformer, and which were the border. Reconstructing that from geometry alone is guesswork, and a diagram silently reassembled from guesses is worse than one that is plainly a picture.
So the import does the honest thing instead. It keeps the drawing exactly as it looks, at high resolution, and puts it behind your work. The longest side of that image is capped at 2600 pixels, which is what keeps a large sheet legible when you zoom into it without the file becoming unwieldy.
What this means in practice
The imported part is a picture. You cannot move a symbol inside it, change a rating on it, re-space its bus, or re-flow it to fit the sheet. Only the symbols, wires and text you place on top are editable.
Read that as a working method rather than a limitation:
- To annotate an existing diagram, import it and add your notes, dimensions and labels over the top. Nothing underneath moves, which is exactly what you want for a mark-up.
- To extend an existing diagram, import it, then draw the new bays, feeders or blocks beside it with real symbols. The new part is editable and exports as geometry; the old part travels as the picture it is.
- To redraw an existing diagram properly, import it and trace over it with palette symbols, then remove the background when you no longer need it. You end with a diagram made entirely of real symbols.
✖ Remove BG removes the background and leaves everything you drew on top untouched.
The background and the CAD export
Because a background is a picture, it stays a picture. Symbols you place are written into a CAD export as real drawing entities; the imported background is not, and cannot be. If the CAD file is the deliverable, either redraw the imported content with palette symbols or accept that only your overlay reaches CAD as geometry. See Exporting the diagram.
Drawing over the background
Switch diagram mode on
Click ⚡ SLD on the plot toolbar, and Hide Layout & Energy Summary to enlarge the working area.
Import the file
Click 📄 Import PDF / DXF and pick the diagram. Its first page appears as the background of the sheet.
Draw what you need on top
Place palette symbols, connect them with Wire, and label with Text. Everything you add is editable and moves independently of the picture beneath it.
Remove the background when you are done with it
Click ✖ Remove BG. Your overlay stays. If you were tracing the imported diagram, this is the point at which the sheet becomes a real diagram rather than a drawing over a photocopy.
Export
The background and the overlay both carry into the exported PDF. Only the overlay carries into a CAD file as geometry. See Exporting the diagram.
Importing your own symbol
🖼 Import Image Symbol adds a symbol the palette does not carry — a make-specific device, a customer's block symbol, a standard glyph your drawing office uses.
The important part is what happens to the image. It is traced into a vector symbol — a set of outlines — rather than pasted in as a picture. Two consequences follow, and both matter:
- It draws as crisp line art. Zoom in and you get lines, not enlarged pixels, and it sits alongside the built-in symbols without looking different.
- It exports to CAD as real vectors. The outlines are written into the drawing file as geometry a drafter can select, move and edit — the same treatment the built-in symbols get.
Imported symbols are stored per user and stay available across sessions, so a symbol you trace once is there in later projects without importing it again.
The symbol editor
Tracing is automatic, and automatic tracing is never perfect. So a Symbol Editor opens first, showing the traced strokes before anything is added to the palette.
- What it shows
- The editor with a traced symbol visible and the three editing tools.
- How to get there
- In diagram mode, import an image symbol — the editor opens on its own. The frame is that editor window, not diagram mode itself.
| Tool | What it does |
|---|---|
| ✏ Pen | Adds a stroke — for an outline the trace missed or broke |
| 🧽 Erase | Removes one stroke — for a speck, a stray edge, or a piece of the background that came through |
| 🗑 Clear | Removes every stroke, so you can start the drawing again |
Work through the trace before accepting it: close the outlines that matter, erase what is not part of the symbol, and check the shape reads correctly at the size it will sit on the sheet.
Two buttons close the editor. Accept adds the symbol, as you have edited it, to your palette. Reject discards the trace and adds nothing.
Deleting a custom symbol
🗑 Delete Image Symbol removes one of your imported symbols. Because these symbols are stored for your user rather than with a project, deleting one removes it from later sessions too.
Tracing a symbol, step by step
Prepare the image
Crop it to the symbol alone, on a plain background, with the line work as dark and as sharp as you can get it.
Import it
Click 🖼 Import Image Symbol and pick the file. The Symbol Editor opens on the traced strokes.
Clean up the trace
Erase anything that is not part of the symbol with 🧽 Erase, and add the strokes the trace missed with ✏ Pen. 🗑 Clear starts the drawing over if the trace is beyond repair.
Click Accept
The symbol is added for your user, so it is available in this session and in later ones. Reject closes the editor without adding anything.
Place it like any other symbol
Click it, then click the sheet. Rotate it with ⟲ 90° or a typed angle, wire it in, and label it with Text.
What traces well
The trace follows outlines, so give it outlines to follow.
| Source image | How it traces |
|---|---|
| A clean line drawing, black on white, no shading | Well — this is the case the trace is for |
| A crisp screen capture of a symbol from a drawing | Well, if the lines are sharp and the background is plain |
| A scan with speckle, or a faint or broken line | Poorly — expect to repair strokes in the editor |
| A photograph of a printed drawing | Poorly — uneven lighting and page curl both read as outlines |
| A shaded or three-dimensional view of the equipment | Poorly — there is no line work to follow, and shading traces as noise |
Two practical habits help more than anything else:
- Crop to the symbol. Anything else in the frame — a title block, a neighbouring device, a caption — traces too, and then has to be erased.
- Raise the contrast before importing rather than repairing the result afterwards. A drawing that is plainly black on plainly white traces cleanly; one that is grey on cream does not.
Where to go next
Symbol reference
What the palette already carries, before you import anything
Building the single-line diagram
Placing, wiring, rotating and labelling on the sheet
Exporting the diagram
Why traced symbols reach CAD as geometry and a background does not
Building a diagram from the plant
Drawing the plant's own chain before you add to it
Building a diagram from the plant
Auto-build draws a starter single-line diagram from the plant's own equipment counts and the materials list's ratings, for you to check and extend.
Exporting the diagram
Three routes out of diagram mode — the report's diagram page, a standalone PDF of the sheet, and a CAD drawing whose symbols are real entities.