internal error

Reinier Geers — Tue, 14 Apr 2026 18:01:59 -0000

Hi ive got an internal error. BUt no solution for this. How do i solve this ?

            ------ Build started: Application: Slave_3.Application -------

[ERROR] Internal error:System.NullReferenceException: De objectverwijzing is niet op een exemplaar van een object ingesteld. bij _3S.CoDeSys.ObjectManager.ExistingPSNode.get_ParentObjectGuid() bij _3S.CoDeSys.ObjectManager.AbstractPSNode.get_ParentNode() bij _3S.CoDeSys.ObjectManager.ProjectStructure.ConsolidateAndClearPendingChanges(LList`1 pendingChanges) bij _3S.CoDeSys.ObjectManager.ProjectStructure.RaisePendingChanges(Boolean bTriggerPendingChanges2) bij _3S.CoDeSys.ObjectManager.Project.HandleUndoMgrAfterEndCompoundAction2(EventArgs e) bij _3S.CoDeSys.ObjectManager.UndoManager.OnAfterEndCompoundAction2(EventArgs e) bij _3S.CoDeSys.ObjectManager.UndoManager.EndCompoundAction() bij _3S.CoDeSys.DeviceEditorSoftMotion.StaticSoftMotionEditor._ehBeforeCompile(Object sender, CompileEventArgs e) bij _3S.CoDeSys.Core.LanguageModel.CompileEventHandler.Invoke(Object sender, CompileEventArgs e) bij _3S.CoDeSys.Core.LanguageModel.CompileEventHandler.Invoke(Object sender, CompileEventArgs e) bij _3S.CoDeSys.LanguageModelManager.LanguageModelManagerConsolidated.OnBeforeCompile(CompileEventArgs e) bij _3S.CoDeSys.LanguageModelManager.LanguageModelManagerConsolidated.RaiseAndCheckBeforeCompile(Guid guidApplication, IMessageCategory cmc) bij ..(Boolean , Boolean , Boolean ) bij _3S.CoDeSys.Compiler35210.CompilerPhases.CompilerPhaseControllerGenerateCode.(Boolean ) bij _3S.CoDeSys.Compiler35210.CompilerPhases.CompilerPhaseControllerGenerateCode.()
Build complete -- 1 errors, 0 warnings : No download possible

Modbus TCP interface get stuck

alexgooi — Tue, 14 Apr 2026 09:24:47 -0000

Dear Forum,

I'm currently experimenting with Modbus interfaces in combination with a virtual controller.

I have the following setup (Modbus_Setup.png):
I have an IPC with Debian installed on it (Debian 13). On this Debian machine I have installed a docker server and on this docker server a Codesys runtime container is deployed (Codesys_image.png).
The Modbus scanner makes connection with and IO coupler and this works well. But when I physically disconnect the ethernet connection between the IPC and the IO coupler the Modbus interface gets stuck in a state where it gets stuck in the busy state (Modbus_Stuck.png). When I plug the cable back in, the IO coupler isn't communicating until the xBusy variable is manually set to False, after this action is performed the communication goes back to normal. I have tried to set the container network to host and bridge (Network.png), but both version gives the same result (stuck scanner).

I would expect that the Modbus interface is generating a timeout after 1 sec, because this is how it is setup (Modbus_settings.png), but this is not what happens. I have thought to write a piece of code that writes xBusy to false when it is stuck but because it is an output I'm not able to write to it.

I have tried this with another PC (different CPU/motherboard) but this gives the same outcome. I tried updating to the latest version of Virtual control (4.20) but this gives the same result.
I also tried to do the same thing with an ethernet IP scanner, and this gives an error after the timeout is expired (so this works well).

I have tried to connect to the IO coupler using the Modbus_FB lib (Modbus_FB.png) the FB's are giving the correct errors and behaving as expected.

At last I have tried to use a Scanner on a Codesys controller (no IPC) and here the scanner behaves as expected (an alarm is triggered after the timeout has been expired).

The version of the Codesys components are listed in the picture Versions.png

Is there anyone that can give me a push in the right direction?

Kind regards Alex

No Bootproject possible

alexgooi — Tue, 14 Apr 2026 08:20:58 -0000

Hello Simon,

Thank you for your response.

The problem occurs after about 10 online changes, after this a full download is required, but that means that the installation is going down.

Is it possible to enlarge the space reserved for online changes, so that the problem occurs after 100 online changes for example?

Kind regards

Alex

Send HTML body with Mail Service SL

msegon — Tue, 14 Apr 2026 08:12:14 -0000

I'm trying to send a mail using Mail service SL.

I would like the body to be in HTML format for a nicer look. Which I managed to do, but only if I don't send an attachment.
Can someone help me with the settings on how to send an HTML body and attachment?

I used the Mail Service SL Example project, the only thing I added in the "Main_PRG" code in line 51 under "SendMailFB" is "mimeType := 1".

I'm using Library:
Mail Service SL Library Documentation
Company: CODESYS
Title: Mail Service SL
Version: 1.13.0.0
Categories: Application|Utils
Namespace: MAIL
Author: CODESYS Development GmbH
Placeholder: Mail_Service_SL

How change Unity-ID in TCP Modbus Slave

nulltrace — Tue, 14 Apr 2026 02:55:54 -0000

Hey, I also waiting for feedback from Mr. Schwellinger
@eschwellinger, please send me an answer, i would appreciate it.

The clue is, i know the solution, but have to check if it's allowed to share.

How change Unity-ID in TCP Modbus Slave

husarz17 — Mon, 13 Apr 2026 20:32:26 -0000

Hi nulltrace,
Thanks for the info. I'm waiting to hear back from you.
Take care!

How to reset scroll of a table element

cv-dse — Mon, 13 Apr 2026 15:17:33 -0000

Hello,

I woulss like to use swipe/pan gestures to scroll a table visualization element (CODESYS 3.5.21.10) ona DSE M810 display.

The swip/pan gesture control works fine, however, I cannot figure out how to reset / navigate to the top of the table again with code.

I have tried the Scrolling begin variable, and the visu manager is setting it to FALSE right away but the table doesn't actually scroll back to top.

If I check the “Scroll elements with scrollbar” box, then the Scrolling begin variable works perfectly, but now the swipe/pan scrolling no longer works and you have to use the scrollbar.

Any assitence you can provide is appreciated. Thanks.

Images not shown in webvisu

pernockham — Mon, 13 Apr 2026 13:44:57 -0000

I must have ended in some kind of limbo between versions, because today after compile/download everything works as wanted.

Movesuperimposed Command Aborted Error

gseidel — Mon, 13 Apr 2026 11:45:53 -0000

Hi transcend,

most likely cause: one of the motion FBs was not called in each IEC cycle.

See https://content.helpme-codesys.com/en/CODESYS%20SoftMotion/_sm_basic_common_errors.html.

A different possible error, if you are using buffermode buffered or blending: the execution order of the motion FBs was wrong. See https://content.helpme-codesys.com/en/CODESYS%20SoftMotion/_sm_buffermode_execution_order.html.

Best regards,

Georg

Sysfile Konfiguration

wollvieh — Mon, 13 Apr 2026 11:25:49 -0000

https://forge.codesys.com/forge/talk/Deutsch/thread/d2df08e587/#3d9c

Recent posts to Talk

internal error

Modbus TCP interface get stuck

No Bootproject possible

Send HTML body with Mail Service SL

How change Unity-ID in TCP Modbus Slave

How change Unity-ID in TCP Modbus Slave

How to reset scroll of a table element

Images not shown in webvisu

Movesuperimposed Command Aborted Error

Sysfile Konfiguration