Post by umdee on Error when monitoring LAD programs ^{CODESYS Forge talk (Post)}
I get the following error when monitoring my program (see attached screenshots): "Unhandled exception has occured in your application. If you click Continue, the application will ignore this error and attempt to continue. If you click Quit, the application will close immediately. Value cannot be null. Parameter name: source. And the details say: See the end of this message for details on invoking just-in-time (JIT) debugging instead of this dialog box. ** Exception Text ** System.ArgumentNullException: Value cannot be null. Parameter name: source at System.Linq.Enumerable.Any[TSource] (IEnumerable1 source, Func2 predicate) at _3S.CoDeSys.NWLEditor.NWLTextCell.OnPaintCellLayer(PaintEventArgs e) at _3S.CoDeSys.Controls.Controls.GfxEdControl.PaintCellCellLayer(PaintEventArgs e, GfxCell cell) at _3S.CoDeSys.Controls.Controls.GfxEdControl.PaintCellCellLayer(PaintEventArgs e, GfxCell cell) at _3S.CoDeSys.Controls.Controls.GfxEdControl.PaintCellCellLayer(PaintEventArgs e, GfxCell cell) at _3S.CoDeSys.Controls.Controls.GfxEdControl.OnPaint(PaintEventArgs e) at System.Windows.Forms.Control.PaintWithErrorHandling(PaintEventArgs e, Int16 layer) at System.Windows.Forms.Control.WmPaint(Message& m) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.UserControl.WndProc(Message& m) at _3S.CoDeSys.Controls.Controls.GfxEdControl.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) ** Loaded Assemblies ** (3000 lines of assemblies) ** JIT Debugging ** To enable just-in-time (JIT) debugging, the .config file for this application or computer (machine.config) must have the jitDebugging value set in the system.windows.forms section. The application must also be compiled with debugging enabled. For example: <configuration> <system.windows.forms jitdebugging="true"> </system.windows.forms></configuration> When JIT debugging is enabled, any unhandled exception will be sent to the JIT debugger registered on the computer rather than be handled by this dialog box The windows show red X's where the networks should be. Any advice on how to fix this? Additional Information PLC used: Wago 750-8212, Firmware FW26 Startup profile: CODESYS V3.5 SP19 Patch 5 OS version: Microsoft Windows NT 10.0.22631.0 .NET version: 4.0.30319.42000 Full Version info attached as .txt
Last updated: 2024-03-17

Post by xcqt on Oop best practice ^{CODESYS Forge talk (Post)}
Hi all, I’m currently trying to improve my OOP structure in CODESYS and I’m looking for some input on how others approach this. I understand the basics like inheritance, interfaces, abstract FBs, methods, and properties, but I still struggle a bit with the overall architecture and what’s considered clean or scalable in bigger projects. As an example, I’m working on two different energy meter function blocks: FB_EnergyMeter_MQTT reads data from MQTT (strings) FB_EnergyMeter_Modbus reads data from Modbus (words) Both have their own Update() method and implement the same interface (something like IF_EnergyMeter). Later on, I’ll probably add more meter types, but they should all behave the same from the controller’s point of view. Now, there’s a FB_GridControl block that needs power data from these meters. I see two options here: Define the meter blocks inside FB_GridControl and call them directly (for example fbModbusMeter.UpdateModbus()). Keep the meter blocks outside and pass them into FB_GridControl as interface references, so the control block doesn’t know which specific type of meter it’s dealing with. Option 2 feels cleaner and more flexible to me, but I’m not entirely sure how to handle the data flow in that case. Should I pass the meter instance through an interface reference (REFERENCE TO IF_EnergyMeter)? Or is there a better way to link the external FBs to the control block? I’d like to hear how you structure this kind of setup or see an example from someone who has done something similar. EDIT: I think i need to do something like this fbModbusUpdateInput(wInput:= wWordValue); fbMqttUpdateInput(strInput:= strStringValue); IF bUseMqtt THEN Meter REF = fbMqttUpdateInput; ELSE Meter REF = fbModbusUpdateInput; END_IF fbControl.SetMeter(UsedMeter := Meter); Or am i thinking wrong? Thanks, Thomas
Last updated: 2025-10-16

Post by vstrom on Codesys v3.5.22.10 - Internal error:System.AggregateException...Value cannot be null...Parameter name: expLValue ^{CODESYS Forge talk (Post)}
Hi to all, I receive an error when I try to compile a project that in v.3.5.21.50 have no problem. The error seems to comes out when I add the Visualization part into the project. The complete error is: [ERROR] Internal error:System.AggregateException: One or more errors occurred. ---> System.Exception: Internal error in Code ---> System.ArgumentNullException: Value cannot be null. Parameter name: expLValue at _3S.CoDeSys.LanguageModelManager.LanguageModelBuilder.CreateAssignmentExpression(IExprementPosition pos, IExpression expLValue, IExpression expRValue, Operator kindof) at _3S.CoDeSys.LanguageModelManager.LanguageModelBuilder.CreateAssignmentStatement(IExprementPosition pos, IExpression expLeft, IExpression expRight) at ..
(IExpression , IExpression ) at ..
(_IAssignmentExpression ,  ) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.AssignmentStatementReplacer.ReplaceExpressionStatement(_IExpressionStatement expressionStatement, _ICompiledPOU cpou) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_ISequenceStatement sequenceStatement) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_IIfStatement ifst) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_ISequenceStatement sequenceStatement) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_IIfStatement ifst) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_ISequenceStatement sequenceStatement) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_IForStatement forloop) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_ISequenceStatement sequenceStatement) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_ISequenceStatement sequenceStatement) at ..
(_ICompiledPOU ) at ..(_ICompiledPOU ) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Codegeneration.
(_ICompiledPOU , _ISignature ) at ..
(_ICompiledPOU ) at ..
(_ICompiledPOU& ) at ..
() --- End of inner exception stack trace --- --- End of inner exception stack trace --- at _3S.CoDeSys.Compiler35220.CompilerPhases.CompilerPhase5_Codegenerator.
(IList1 ) at _3S.CoDeSys.Compiler35220.CompilerPhases.CompilerPhase5_Codegenerator.
(IScope5 , IList1 ) at _3S.CoDeSys.Compiler35220.CompilerPhases.CompilerPhase5_Codegenerator.
(ICodegenerator ) at _3S.CoDeSys.Compiler35220.CompilerPhases.CompilerPhaseControllerGenerateCode.() at _3S.CoDeSys.Compiler35220.CompilerPhases.CompilerPhaseControllerGenerateCode.() ---> (Inner Exception #0) System.Exception: Internal error in Code ---> System.ArgumentNullException: Value cannot be null. Parameter name: expLValue at _3S.CoDeSys.LanguageModelManager.LanguageModelBuilder.CreateAssignmentExpression(IExprementPosition pos, IExpression expLValue, IExpression expRValue, Operator kindof) at _3S.CoDeSys.LanguageModelManager.LanguageModelBuilder.CreateAssignmentStatement(IExprementPosition pos, IExpression expLeft, IExpression expRight) at ..
(IExpression , IExpression ) at ..
(_IAssignmentExpression ,  ) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.AssignmentStatementReplacer.ReplaceExpressionStatement(_IExpressionStatement expressionStatement, _ICompiledPOU cpou) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_ISequenceStatement sequenceStatement) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_IIfStatement ifst) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_ISequenceStatement sequenceStatement) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_IIfStatement ifst) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_ISequenceStatement sequenceStatement) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_IForStatement forloop) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_ISequenceStatement sequenceStatement) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Optimization.ExpressionStatementReplacerVisitor.visit(_ISequenceStatement sequenceStatement) at ..
(_ICompiledPOU ) at ..(_ICompiledPOU ) at _3S.CoDeSys.Compiler35220.Phase5_Codegeneration.Codegeneration.
(_ICompiledPOU , _ISignature ) at ..
(_ICompiledPOU ) at ..
(_ICompiledPOU& ) at ..
() --- End of inner exception stack trace ---<---
Last updated: 2026-04-22

Post by rmarco on Generic Variables and FDB ^{CODESYS Forge talk (Post)}
Hello everyone, I am running into a highly frustrating issue in the FBD editor regarding a Function Block with generic constants (VAR_GENERIC CONSTANT). I created a FB using ST, with a generic var, useful for having a variable sized array, as follows: FUNCTION_BLOCK Coil VAR_GENERIC CONSTANT maxEvents: USINT := 5; END_VAR VAR events: ARRAY[0..maxEvents-1] OF IEvent; END_VAR These FBs have also several methods. I declare them as follows in code: VAR coil1: CDL.Coil<(maxEvents:=1)>; END_VAR and when using them in ST, I have no problems. However, when trying to use them in FDB, I do not know how to do that, as some strange misalignment happens. Here's what happens: When I add the block to my FBD canvas and assign coil1 as the instance name, the compiler throws this error: 'coil1' is not an instance of 'CDL.Coil<(maxEvents:=1)>'. Same occurs when I try to instantiate blocks such as 'coil1.turnOn' or similar. Here is what I have already tried, none of which worked: - Deleting the <(maxEvents:=1)> parameter from the text inside the FBD box. - Deleting the block entirely, dropping an "Empty Box", and typing coil1 above it to let the IDE auto-complete and format the block. - Running a full "Clean All" and rebuilding the code. I am aware that I could bypass the graphical editor by calling it in Structured Text. However, I need to keep this logic compatible to FBD. Has anyone encountered this specific FBD parsing bug with generic variables? Thanks in advance for any insights. Best regards, Marco
Last updated: 7 days ago

Post by deeps on web visu on IFM ^{CODESYS Forge talk (Post)}
I have an IFM cr1077 display. I would like to show B&R mapp view on IFM visualization. I used coedsys web browser elemnt for this. I could see IFM working fine in Internet web browser but IFM device shows white screen and freezes. I think there is problem with IFM showing the web browser. Is my understanding of the web visu right? am I doing any mistake here?
Last updated: 2023-08-18

Post by gerdkoch on Dynamic I/Os Mapping ^{CODESYS Forge talk (Post)}
Hi, I assume that you have a Pfc200 G2 or something and work with the original WAGO runtime. Then I would recommend the WagoSysDynamicIoMapping. Here in the example projects there is a PDF file for the library: https://downloadcenter.wago.com/learning-material/details/ll0w3pmdunzvem83g1 There is a global functional component in a GVL of the library. I think it's called DynKbusIoManager or something. The active terminals are registered there. Then there are filter Fb's for e.g. the first clamp with a specific article number. Everything is in the PDF.
Last updated: 2023-08-18

Post by rossanoparis on After un upgrade of "CODESYS Control for Raspberry Pi MC SL" from v4.7 to v4.9 SysFileOpen function stopped working ^{CODESYS Forge talk (Post)}
For those who will step on this thread. Everything is fine, I had only to increase by 1 my place holders number. For sure the system is occupying the number 1 without being declared ... Below the modification I made to get my code working. [SysFile] PlaceholderFilePath.2=/home/pi/hpca/bin, $hpcabin$ PlaceholderFilePath.3=/home/pi/hpca/cfg, $hpcacfg$ PlaceholderFilePath.4=/home/pi/hpca/logs, $hpcalogs$ PlaceholderFilePath.5=/home/pi/hpca/resources, $hpcares$
Last updated: 2023-08-22

Post by t-probst on Strong Private Key Protection for Encryption Certificates ^{CODESYS Forge talk (Post)}
Hello, We are trying to implement an automated method of adding of a certificate and private key to the Windows certificate store for encrypting CODESYS projects. We want to do this so that users do not have to deal with details of certificates at all and to prevent user error. We are keen on enforcing strong private key protection since it ensures that a password is required for the certificate to be used to decrypt a CODESYS project. When we add a certificate to the certificate store and enable strong key protection using the Microsoft Management Console Certificates snap-in, it works as expected. However, through this method the user may mistakenly not enable strong private key protection. For the certificates we create programmatically (using Microsoft’s Cryptography Next Generation API in .Net 7) bag attributes are added to the certificate and key by the API. These bag attributes are as follows: Bag Attributes localKeyID: 01 00 00 00 subject=C = xx, ST = xxx, O = xxx, OU = xxx, CN = xxx issuer=C = xx, ST = xxx, L = xxx, O = xxx, OU = xxx, CN = xxx -----BEGIN CERTIFICATE----- [encoded certificate] -----END CERTIFICATE----- After using this certificate with bag attributes to encrypt a CODESYS project, it can’t be decrypted, showing this error: "The specified project could not be loaded. Possible reasons might be: - The project file is corrupted or invalid - The project has been saved with a newer version of the programming system. If this is the case, you can open the project in the corresponding version. Choose "Save as..." with the appropriate storage version, and retry again. - You may not have the necessary permissions to lad the project" We know that the bag attributes are causing the issue because if we manually edit the certificate file to remove them before using the certificate to encrypt a project, the project can be decrypted as expected. However, we are unable to automatically enforce strong key protection using this method. Here is a link to a StackOverFlow question that we have posted recently for this issue: https://stackoverflow.com/questions/76922355/enforcing-strong-private-key-protection-for-x509certificate2-objects-in-net-mod Any help is greatly appreciated.
Last updated: 2023-08-22

Post by kreisfilho on Stop raspberry from executing a plc program ^{CODESYS Forge talk (Post)}
Hi guys, Can someone inform where in a raspberry pi are stored the codesys programs? I´ve been training the use of a RPI as PLC, which works pretty well, however while both the RPI and PC (running codesys) remain connected to the same network. The question is: how to run the codesys program downloaded to the RPI as a stand alone device (disconnected from the PC)? Thanks! Kreis
Last updated: 2023-08-23

Post by ernesto881124 on ernesto881124 ^{CODESYS Forge talk (Post)}
Hello good morning everyone I would like to ask a question, is it possible to directly connect a device that only contains modbus RTU communication through an R-45 connector, directly to the PC? Or would you need an intermediate device to achieve communication? It would be of great help to me because I cannot achieve communication between the Codesys simulator plc and a Fuji Frenic mini VFD, please help me if anyone has had the same experience. Thank you so much
Last updated: 2023-09-13

Post by timvh on Specify Input Configuration "OnDialogClosed" Action to only react to certain Dialogs ^{CODESYS Forge talk (Post)}
What maybe helps is the Visu Dialog ST demo project: https://store.codesys.com/en/visu-dialog-st.html This has an application IECOpenDialog where dialogs are opened using the VU.FbOpenDialogExtended function blocks. The fbOpenConfigurationDialog call has a reference (interface) to the "close listener" FB of which it's method is automatically called when the dialog is closed. This way you can create specific function blocks for each dialog when it is closed and do what you want with the data that might have been changed.
Last updated: 2023-09-28

Post by damian177 on Codesys MQTT subscribe ^{CODESYS Forge talk (Post)}
Hi, In my project I have MQTT Client like below: //mqtt client mqttClient( xEnable:=connect_to_broker, sHostname :=sHostname, uiPort:= uiPort, xUseTLS:=FALSE, wsUsername:="", wsPassword:="", xCleanSession:=TRUE, sClientId:='694d45587761676f4b6f6e74656e6572', pbWillMessage := ADR(sWillMessage), uiWillMessageSize:=DINT_TO_UINT(Stu.StrLenA(ADR(sWillMessage))), xWillRetain:=FALSE, udiTimeOut:= 10000000); And ten subscriber's , one of those is below: //subscribe a topic1 mqttSubscriber_S1(xEnable:=subscribe, eSubscribeQoS := 0, pbPayload:=ADR(sSubscribeMessage_S1), udiMaxPayloadSize :=SIZEOF(sSubscribeMessage_S1), mqttClient:=mqttClient, wsTopicFilter:=wsSubcribeTopic_S1); TerminateString(ADR(sSubscribeMessage_S1), mqttSubscriber_S1.udiPayloadSize); After connected to broker I set subscribe to TRUE in alls subscribers and my mqttclient recive error : ACKNOWLEDGE_TIMEOUT what can be wrong ?
Last updated: 2023-10-11

Post by sukrit on What licenses are required for runtime on raspberry pi cm4 ^{CODESYS Forge talk (Post)}
We have developed a project for 2 servo motors using raspberry pi computemodule 4 on ethercat master. we are using web visualization for display different screens. project is running well in demo. we want to implement it in production envoirment. being new still wondering which licences i need. Can We get this information in codesys devlopment software. code size is approx 5 mb, 1 instance of etharcat master and aproox 100 variables in visaualization.
Last updated: 2023-10-17

Post by davidbo on RPI How to login for a copy of the SD image ^{CODESYS Forge talk (Post)}
I had one RPI device where I could login. I copied the SD-flash over to another SC-flash. This new SD-flash was inserted in the new device. I can boot the new device but I cannot login why? How can I install an application on this new device? Control 4.4.0.0 cat os-release PRETTY_NAME="Raspbian GNU/Linux 11 (bullseye)" NAME="Raspbian GNU/Linux" VERSION_ID="11" VERSION="11 (bullseye)" VERSION_CODENAME=bullseye ID=raspbian ID_LIKE=debian HOME_URL="http://www.raspbian.org/" SUPPORT_URL="http://www.raspbian.org/RaspbianForums" BUG_REPORT_URL="http://www.raspbian.org/RaspbianBugs"
Last updated: 2023-10-18

Post by john-martin on Send file from codesys to...... ftp, cloud, etc ^{CODESYS Forge talk (Post)}
Hi everybody, I am looking for a solution to send files, for example, to an ftp or a cloud. I can't use oscat library because 64 bit controller are not supported. Therefore, I see that the IIoT library has some functions that might help me to implement this sending process in codesys. Does anyone have any examples of how to do this? I have spent some days with this issue without success. Best regards.
Last updated: 2023-11-02

Post by davidbo on How to allow a user to handle certificates without access to sourcecode? ^{CODESYS Forge talk (Post)}
With CODESYS V3.5 it is possible for a user to do the following things among many others. 1) Handling certificates especially move a certificate to the trusted folder. 2) Change password and create new users for OPC UA access However it requires access to the whole projects and its source code. Something you might not want to hand over to an end user for a stand alone product. Is there a way out of this problem?
Last updated: 2023-11-06

Post by ekristoffe on Beispieldateien finden / Inhalt der Packages ^{CODESYS Forge talk (Post)}
Hello @eschwellinger, Why not using one of those 2 folders: C:\ProgramData\CODESYS C:\Users\Public\Documents\CODESYS The main reason is depending on the company and the user right, the end user may not have the access to use those folders. Also having a non version dependent folder may help if the end user uninstall a previous version and forgot all its sample project where in this previous version installation. Thanks.
Last updated: 2023-11-24

Post by joanm on Tab control element, hide/show tabs programatically? ^{CODESYS Forge talk (Post)}
Hi all, Is it possible to hide or show tabs from the PLC code? I have created a few tabs in my visualizations to configure the program behavior, I'd like to be able to hide some of them if the related option in the main tab has been disabled. Is that possible? if so, how should I do it? Thank you all in advance.
Last updated: 2023-11-25

Post by alink on Visu - changing auto-logout time ^{CODESYS Forge talk (Post)}
Hello is there a chance to set with a visu input the auto-logout time? At the moment, it is a fix value set in visu-manager. But for individual configurating of passwort policies I create a visu-dialog to set policies and there for an option to set auto-logout-time. But till now, I haven't found a solution. Maybe someone has an idea? Thanks
Last updated: 2023-11-30

Post by macros8 on Alarm Management - Import and Export of AlarmGroup ^{CODESYS Forge talk (Post)}
Hi, I struggle with exporting my Alarm Messages and following importing back to my project. Because filling in one by one is very time consuming I want to use export function and edit .csv file in Excel. As soon as I modify the file the import back to project does not work at all and function returns errors. Would you pls give me a hint how to properly use this functionality? Thanks a lot for help. Regards, M.
Last updated: 2023-12-02

Post by jeffg on License issue with visu tags ^{CODESYS Forge talk (Post)}
I seem to be having a problem with the license on ver 3.5.19 patch 5 The runtime keeps going into demo mode but it wont tell me the reason I looked at the license software metrics and the visu doesn't appear to be working I attached screen shots of the metrics screen and the license dongle that is plugged in to the windows PC Anyone have any ideas on how to fix this
Last updated: 2024-06-28

Post by rafael on Access to user group IDs ^{CODESYS Forge talk (Post)}
Hello, I'm trying to access the group IDs of the connected user. "CurrentUserGroupId" var shows only the first group ID that the user is assigned, I need the other group IDs that the user is in. I find some structs but I can't find where they are used, like "VUM_User" scruct from visuusermgmt, where can I find this vars? https://content.helpme-codesys.com/en/libs/VisuUserMgmt2%20Interfaces/Current/VUM_User.html abyUserGroupIDs seens perfect but I can't find a GVL where it is used.
Last updated: 2024-07-08

Post by srouse on PFC200BUS not running ^{CODESYS Forge talk (Post)}
I started a project in codesys for a WAGO 750-8212 PLC and I am working on getting online with the controller. I can log in to the controller and I can see and control all of the fieldbus couplers that I have. I am unable to get the internal bus working. It just says that the bus is not running and when I scan or devices nothing shows up. Am I missing something important in my device tree?
Last updated: 2024-07-10

Post by mandeepahujaifm on Ethernet/IP 4.6.0 causing exceptions? ^{CODESYS Forge talk (Post)}
I have experienced the same with one of our customers after updating EIP Scanner to 4.6.0.0 and really baffled by it. The core dump simply shows error with ENIPScanner I/O task and on analyzing it says no source code available for 4.6.0.0. Contemplating to go back to 4.5.1 but 4.6.0.0 has some really nice fixes. I guess it don't matter if it crashes anways. Please keep us posted if you find anything.
Last updated: 2024-07-11

Post by timvh on No source code available for this object ^{CODESYS Forge talk (Post)}
The message means that you (CODESYS) tries to open the function block, but this is not possible because the library which contains the FB is compiled. You either get this when you try to manually open the function block (while editing the application), but it could also happen that an exception occurs in the running application and CODESYS tries to show the location where it occured. If it happened in an FB of the compiled library, it cannot show this and you could get this message too.
Last updated: 2024-07-16

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