If opening an object to edit its tag pins the editor at 100 percent CPU, measure free RAM and compare it with the software's stated free-RAM requirement before touching the project. A machine whose installed RAM only equals the required free RAM can never pass, so the editing moves to a machine that meets the line, and a CSV export into a fresh project separates a computer limit from a damaged project.
When a click on a screen object to edit its tag pins the processor at 100 percent and the editor has to be killed, check the machine before you touch the project. Read the machine's free memory and compare it with the free-RAM figure in the programming software's specification. A laptop whose installed RAM only equals the requirement in free RAM cannot meet it, because Windows holds part of that memory from the moment it boots. On such a machine, every reinstall and every trimmed background process fails for the same reason. One comparison then settles the rest: export the tag database to CSV, build a fresh project with a simple screen, import the tags, and repeat the same click on a machine that meets the requirement. Where the hang follows tells you whether you are fighting the computer or the project.
What the symptom points to
Each observation below narrows the cause. Read them in Task Manager on the programming laptop.
- The processor hits 100 percent the instant an object opens for tag editing, with the editor's process at the top of the list. The machine's free memory is the first suspect and the project file is the second; the checks below order them.
- The hang survives a software reload, closing every other program and clearing disk space. Stop repeating those steps. They change neither the installed memory nor the requirement, so they cannot change the outcome. The example below shows the arithmetic.
- The same click behaves on a different machine. The project data is sound; the first machine misses the requirement.
- A fresh project with the same tags hangs on the same machine. The fault sits with the computer or the installation, not the tag data.
- The panel on the machine is what blanks and freezes. That is a separate fault with its own first step: check power first before you touch the laptop.
Installed RAM and free RAM are different numbers
Specification sheets for programming software write the memory line two ways: installed RAM and free RAM. The wording decides this fault.
Installed RAM is what the machine carries. Free RAM is what remains while Windows, its drivers and every running process hold their shares, with the editor itself loaded. Free is always the smaller figure, and the gap is at least the operating system's own footprint.
So a line that reads a value as free cannot be met by a machine that carries exactly that much installed. The shortfall exists before the editor starts. Trimming background processes narrows the gap and cannot close it, because the OS share is fixed.
The same reading applies now at larger sizes. Current engineering suites publish requirements in the 8 GB class, and buyer guides for programming laptops recommend 16 GB installed. A laptop below that installed figure against an 8 GB requirement misses the line before the software starts, by the same arithmetic.
Read any memory figure with that habit. A number shown on a control display can be capacity, not usable RAM, and a spec line can say installed where the software needs free.
Example: installed RAM equal to a free-RAM requirement
Inputs. A programming laptop runs Windows 2000 with 128 MB of RAM installed; read that figure from the machine's memory count at boot or in Task Manager. The editor's specification calls for 128 MB of free RAM. The open project holds about 300 tag names for a 15-inch touch panel. The deciding figure, free RAM, is read from Task Manager while the editor and the project are open.
Rule. Free RAM at the moment of the click equals installed RAM minus the memory Windows holds, minus the memory of every running process, including the editor itself. A requirement written as free must hold at that moment.
Arithmetic.
free RAM at the click = 128 MB - (Windows 2000 share + background processes + editor with the project open)
The Windows share is greater than 0 MB from boot; its exact size is not published on the specification, and the comparison does not need it. Any positive share puts free RAM at the click strictly below the 128 MB requirement, before any other term is counted. Every process that runs pushes it lower by its own footprint.
Result. The laptop fails the free-RAM line by at least the size of the OS share, before the tag data is even considered. Reinstalling the editor and trimming the project cannot change this. Only the machine or the requirement can.
Decision. The machine passes only when free RAM reaches the requirement at the moment of the edit. With 128 MB installed against a 128 MB free line that is arithmetically impossible, so tag editing moves to a machine with more memory. Where a sheet states a recommended figure, take it: one requirements sheet for this class of software lists 512 MB as recommended against the lower minimum, and the recommendation is the margin that leaves the required free RAM actually free.
The comparison that splits a project fault from a machine fault
The comparison changes the project container and keeps the tag data, so a result points at one of the two. Run it on a machine that meets the free-RAM line; on the short machine the result proves nothing about the data, because the shortage sits over both projects.
Save a copy of the original project to a second location first. Every test runs on copies, and the working original stays untouched. Then:
- In the editor, export the tag database to a CSV file and keep the file.
- Create a new project with one simple screen.
- Import the tag database from the CSV into the new project.
- Open an object on the new screen and click to edit its tag, the exact action that stalls in the original project, and watch CPU and memory in Task Manager.
- Repeat the same click in the original project under the same conditions.
The CSV has a second life as a portable tag list for other tools; building a CSV tag list from a symbol export works the same file from the other side.
| Result | What it points to | Next step |
|---|---|---|
| New project hangs too, on the short machine | The shortage sits over both projects, so the run is blind to the tag data | Retest both projects on a machine that meets the free-RAM line |
| New project behaves, original hangs, same machine | The machine stayed constant and only the project changed, so the original project file is the suspect | Confirm on an adequate machine, then escalate the original project |
| Original hangs alone, machine meets the line | The fault follows the project data | Send the original project and the test project to the software vendor, with your readings |
| Both projects hang, machine meets the line | The fault sits in the installation or deeper | Send the reproduction steps, the readings and both projects to the software vendor |
| Both behave, machine meets the line | The first laptop was the cause | Upgrade that machine or retire it from tag-editing work |
The comparison locates this hang; it does not certify the rest of the original project.
Checks, in order
- Read installed RAM and free RAM in Task Manager before the editor starts. Write both down with the time.
- Compare free RAM with the free-RAM line in the specification. A machine that misses the line with the editor closed misses it worse with the project open. If it misses, close every other application and read again; if it still misses, move the editing work to a machine that meets the line.
- On the adequate machine, run the comparison above and read the result against its table.
- Verify the outcome on the edit action itself. Open several objects, click to edit their tags, and confirm the editor stays responsive with CPU back to idle between clicks.
- If the original project alone still hangs on the adequate machine, stop and prepare a support package: the editor build string, the panel's firmware revision, which deserves its own check before a project transfer, and the memory readings from step 1. The FAQ lists the rest of the package.
The decision
Recommendation: Read free RAM in Task Manager before you touch the project again. If free memory cannot reach the software's stated line, move tag editing to a machine that meets the line, and run the CSV comparison there before you treat the project file as damaged: a damaged project is a finding the CSV comparison is designed to produce, so let it produce that result before you assume it. Keep the working original untouched through every test, and let the table pick the next step.
This fault lives in the programming laptop. The display on the floor is a different machine with its own power and environment needs; if you also run a status or notice board, the shop-floor screens section covers that side.
Questions
Why does 100 percent CPU appear before I edit anything?
The stall arrives when the object opens, before any tag changes, so the editor is gathering the object's tag information at the moment it locks. That timing points away from the size of the edit and toward the state of the machine: with no free memory, the work cannot finish, and the process holds the whole processor until you end it. The database in this fault held about 300 tag names, a small load for an editor, which is why memory ranked first.
How much RAM does current HMI programming software need?
Read your own suite's sheet, and check whether the memory line says installed or free. Requirements have grown with the software: one current engineering suite lists 8 GB of RAM and 20 GB of free disk space to install. Older generations stated the figure as free RAM, in the tens of megabytes on one specification, which is the wording that decides this fault.
Should I reinstall the programming software when tag editing hangs?
A reload replaces program files and leaves the project data alone, so it cannot repair a damaged project. It cannot fix a memory shortfall either: the fresh install runs on the same machine, against the same requirement, and lands in the same shortage. In this fault a reload had already been done and the hang returned, which is the expected result on a short machine. Reinstall only if a machine that meets the free-RAM line still shows the fault.
What do I send support when the CSV test is ambiguous?
Send the original project and the CSV test project as files, the full editor build string, the Windows version, the installed and free memory readings, the tag count, and the exact click written as steps. With those, support can reproduce the hang on a machine that meets the requirement and inspect the project themselves.
Planning information, not legal or engineering advice. Rules differ by place: check codes and permits with your local authority and your licensed trades.