Troubleshooting

A list of the actual messages the system prints and what is really behind them. When a build fails, the editor opens a window with the whole output — the text can be selected with the mouse and copied with a button, and the same text is in build\last_build_error.txt.

Downloading a program

"the ST compiler (visu_stc) was not found"

The ST compiler is missing. Since ladder and FBD compile to bytecode, every project with logic needs it.

Installed editor: visu_stc.exe must stay next to visu_editor.exe. If you moved files, put it back or reinstall.
Repository clone: either use the binary from dist\, or build the compiler: cmake --build build --target visu_stc.

"the ST compiler … is schema v16, this builder is v17"

The three installed binaries do not come from one build — an update replaced some and not others. The editor, the pack builder and visu_stc carry the schema version they were built for and check each other, because a mismatch used to surface as nonsense further down ("TON has no member 'ET'"). Reinstall ctrl32 so all three come from the same release.

The same message about the pack builder means packbuild\ next to the editor is older than the editor itself.

"tag 'NOT' has the name of an ST keyword"

A tag becomes an identifier in the generated program, so a name like NOT, VAR, REAL or TIME means something else there. Rename the tag — the message says which one.

"EQ 'b30': its parameters have no ST form yet"

A block the editor can draw but the generator cannot yet translate. The message always names both the type and the name of the block. Report it to bugs@ctrl32.com — it is usually a small fix.

"logic cannot compile to bytecode: … did not compile"

The generated program failed to compile — that is our fault, not your project's. The editor prints the whole generated source with line numbers; send that output.

"project has N blocks, the limit is 512"

A real limit. See Performance and limits; usually the tag table runs out first.

The panel

The panel refused the pack ("invalid pack")

The pack failed verification — most often the target board does not match (the project is for another panel), or the runtime is older than the pack format.

Important: the old pack stays and keeps running. A download cannot disable the panel. The fix: check the board in the project, or flash the runtime.

"!! N FB RECORDS – this pack predates the one-engine build"

The panel holds a pack from a very old editor. Its logic does not run — the panel says so on the console and in the diagnostic buffer. Rebuild the project with the current editor and download it again.

The panel answers but `seq` does not move

The connection is fine; the PLC cycle has stopped. Look at the diagnostic buffer (Debug → diagnostics) — the reason is usually there (a VM fault, a cycle overrun).

Online monitoring

The plug icon is red

The panel runs a different program than the editor. Values are deliberately not shown — they travel by index, and under a different program they would appear as real numbers under the wrong names. The editor offers to download straight away.

The icon is amber and nothing happens

The port cannot be opened: another program is holding it (a terminal, another editor), the panel is restarting, or the cable is unplugged. It retries once a second, so plugging the cable back in is enough.

The port list is empty, or nothing is selected

No port is preselected on purpose. Pick one in the toolbar or in the transfer dialog — the download and flash buttons stay disabled until you do.

I see tags but no values on the wires between blocks

The symbols could not be verified — the editor uses them only when the compiled program matches the one in the panel byte for byte. It writes the state into the status bar; the usual cause is that the panel holds a different build.

ONLINE and Deploy are locked

The licence is missing. Editing and simulation work without one; talking to a real panel is the paid part.

The editor

A new project will not take a rung

This was a bug and it is fixed: the + Rung button now creates a BOOL tag itself and says which one. If it still does not work, you have an old binary.

A comment next to a variable disappeared

Also fixed. The comment is written at the end of the line after // and read back; leaving the line without one deletes the comment — the text is the whole truth for its list.

An opened project has an empty ladder

A fixed import bug (the project was being loaded through a pack without block records). Update the editor.

If a problem does not fit here, send the whole error output (the Copy message button) to bugs@ctrl32.com — the bug icon at the top right of the menu opens the mail directly.