The engineering laptop died last week. Hard drive. The only copy of the mixer project was on it. No backup, don't ask.
Uploaded from the controller today, 1756-L72, Studio 5000 v32, on the other laptop. Upload went fine and it's all there, every routine and every tag, but no rung comments and no tag descriptions at all. 1400 tags with nothing on them, and the old file had the lot commented. I tried again with the Ethernet devices driver instead of the EtherNet/IP one, and off a different laptop with v33 on it, same both times.
Is that just what upload does, or did the firmware update in June strip the comments out? Not sure if there's anywhere else they could be hiding in the controller, and 1400 tags is weeks of typing if there isn't.
That's just what upload does unless the last download stored the documentation in the controller. From v21 on there's a Controller Properties setting for it, Project tab if I remember right, download project documentation, and the default is off. If it was off at the last download, the comments never went into the controller and no upload will find them. Firmware on the L72? And any older .ACD anywhere at all, USB stick, email, the OEM?
32.011. Found a 2023 .ACD on a USB stick in the drawer, from before the June changes. Pretty sure that one has the comments, but it's a year out of date on the logic.
There's your comments. Don't download the 2023 file, compare it against the upload.
Compare first. Open the fresh upload, then Tools, Compare, or the Logix Designer Compare Tool from the start menu, against the 2023 file, it shows which rungs and tags match. Tag descriptions: Tools, Export, tags and descriptions from the 2023 file to CSV, then Tools, Import into the upload. Same name gets the old description, new tags stay blank and you write those. Rung comments are the slow bit, where the compare says the rung is unchanged you copy the comment across by hand. Then download once with the project documentation box ticked, Controller Properties, Project tab, so the next upload keeps them. Writeup on keeping documentation in the controller: https://plctr.com/best-practices-for-plc-program-documentation/
Tag export from the 2023 file, import into the upload. 1310 of 1400 descriptions came back, the rest are June tags and I'll write them. Rung comments I'm doing by hand from the 2023 file, compare open on the other screen, about half done.
Then downloaded on the weekend shutdown with the project documentation box ticked. Uploaded again after to check. Comments came back.
So the last download never stored the documentation in the controller and upload had nothing to give back. Import from the old file, then download with the box on.
Still don't know why that box is off by default. Backups every Friday now, on a drive that isn't a laptop.
Thanks rsdave and carlh.