Use SCR + AutoLISP to Process Multiple DWG Files
Combine AutoCAD startup scripts with small AutoLISP commands when a job must open many DWGs, run controlled checks and then plot or publish.
Main idea: Use SCR for predictable drawing-to-drawing playback and AutoLISP for the logic inside each drawing.
Best use: Folder-based standards updates or repeated plotting where each DWG needs the same internal command.
Start with the manual workflow
Prove the command inside one DWG before you automate opening many files. Multiple-DWG automation multiplies every mistake.
Before automating a production workflow, review Autolisp Vs Scr Plot Automation, Autolisp Validate Plot Settings Before Batch, and How to Publish Multiple DWG Files to PDF in AutoCAD.
Build the automation in small layers
Step 1 — Stabilize the in-drawing command
Where: One DWG
Do this: Make one AutoLISP command complete its work and exit cleanly.
Check: It does not need manual clicks.
Step 2 — Create the script sequence
Where: SCR file
Do this: Open/run/save/close only as required by the workflow.
Check: The script can be replayed in a test folder.
Step 3 — Use command-line startup when needed
Where: AutoCAD /b on Windows or -b on Mac
Do this: Launch a drawing with a script after confirming platform syntax.
Check: Automation starts predictably.
Step 4 — Keep output and logs outside source DWGs
Where: Dedicated folders
Do this: Write PDFs/reports to controlled paths.
Check: Original files remain easy to recover.
Step 5 — Test failure behavior
Where: A deliberately bad DWG
Do this: Confirm the batch does not silently continue after a critical error.
Check: Operators can identify the failed file.
A safer multiple-DWG pattern
Start with a read-only command such as “write a plot-settings report,” then run that command across a folder with a script. If that works reliably, move to PDF generation. Only after those stages should you consider routines that save changes back into every DWG.
This progression matters because an unattended batch can change hundreds of files before anyone sees the first mistake. Backups and logs are not optional once the automation starts modifying source drawings.
What the code should control
- SCRIPT/SCRIPTCALL
- AutoCAD startup /b or -b switch
- AutoLISP command availability
- SAVE/CLOSE policy
- Output/log path
What you should deliberately leave manual at first
Do not enable automatic SAVE across hundreds of drawings until the in-drawing changes are read-only or fully proven and backed up.
Failure modes to design for
- A script prompt changes between releases.
- A drawing opens with missing xrefs/fonts and the batch still saves it.
- Startup security prevents the LSP from loading.
- One failed DWG leaves the script at a different command prompt state.
When this becomes a production tool
Separate read-only audit batches from modifying batches. The first can be widely used; the second needs backups, logs and rollback planning.
Official Autodesk references
Frequently asked questions
Why combine SCR and AutoLISP?
SCR is good at fixed command playback; AutoLISP is better at decisions and drawing-state checks.
Can this run unattended?
It can, but unattended modification requires stronger error handling, backups and testing than a simple tutorial routine.
Should the batch save every DWG?
Only if saving is an intentional, tested part of the workflow.
Explore more in AutoLISP Plotting & PDF Automation.