Post by dandyk on Dynamic Images ^{CODESYS Forge talk (Post)}
Hello, I have very similar problem, but it seems that your solution does not work for me. I am using TwinCAT XAE Shell v3.1.4024.55 and TwinCAT Runtime. Sorry for writing here on codesys forge, but since I found the only relevant topic here and since TwinCAT is almost the same with CODESYS in many applications, I chose to write here. I simply need to dynamically update image in visualization based on camera trigger (I am doing a machine vision application). Camera triggers an image, my program processes it (applies thresholding, draws contours etc...) and saves the processed image in the runtime location (the same one you were mentioning). This was done successfully. I need to make it work at runtime, while the program is executing and I need to refresh the image in the visualization each time camera triggers a new image and program processes it. When I create image element in the visualization and define the bitmap ID variable as STRING which contains the image ID defined in the image pool, then it displays the image in the image pool, but does not work at runtime, while the program is executing. I also used the Bitmap Version. I declared it in Global variable list as integer with initial value of 0 and wrote the variable in the bitmap version in the image element in visualization. Each time new image is saved to the runtime location, I wrote a program to increment Bitmap Version by 1. It increments and the image does not update in the visualization, unfortunately. I think that bitmap version is working correctly and deletes the cached image as it is supposed to, but the Image Pool does not update the image ID with the new image... the path to the image is always the same... only the actual image changes with the same file name. Image Pool is not dynamic and cannot refresh the image in the path to the actual one at runtime. How can I refresh the image ID in the image pool at runtime? Bitmap version only deletes cached image and reloads the image from the image ID, but the image ID has the same image, because image pool won't update at runtime. Do you know any solution to this problem?
Last updated: 2024-04-06

Post by jerry-sorrells on Find Function: Object reference not set to an instance of an object. ^{CODESYS Forge talk (Post)}
Build: CODESYS 3.5 SP19 Patch 1 (64-bit) Host OS: Windows 10 Target: Linux SL I have a project with programs in Structured Text and Ladder Diagram. When I try to use the Find function, it works for the Active Editor; however, when I try to use Find for the Entire Project, I get the error "Object reference not set to the instance of an object." I know what this error means in the context of the program, but I have no idea why the find function is returning this error. The variable I am searching does not matter: it happens with all variables. Any help with this will be greatly appreciated. I generally use the Find function quite often as I am developing and not having it is really slowing me down.
Last updated: 2023-10-23

Post by alimans on OPC-UA Server, Symbol Set: Raise an error: Object reference not set to an instance of an object. ^{CODESYS Forge talk (Post)}
Hi everyone, I just created a very simple library without any code and, added it to my very simple project. after adding this library, I get an error when I try to open "Symbol Set" in "OPC UA Server" in "Communication Manager". Here is the code of my POU in the library: FUNCTION_BLOCK POU VAR eCommand : (CMD_NONE:=0, CMD_RESET:=-1) INT := CMD_NONE; END_VAR Attached is the error that I get. I also noticed that by removing the enumeration variable above (eCommand), I can open the "Symbol Set" again. Anybody has any idea why this error is raised and how could I use enumeration variables without error in "OPC UA Symbol Set"?
Last updated: 2024-08-08

Post by cfam on Codesys Control for PLCnext SL, Bus not running ^{CODESYS Forge talk (Post)}
Good day I would appreciate it if you can give me some advice on how to fix my "Bus Not Running Error". I am Using Codesys 3.5 SP20 and Codesys Control PLCnext SL V4.12.0.0. Codesys control was installed on the device and I can log into it but it seems that it does not pick up the PLC or the IO attached (Please see attached Image). The Bus Cycle Task of the AXL F 2152 is set to Main Task and the "Always update Variable" is Enabled on each IO Module. My Main Task interval is set to 100ms and Priority is set to 0. I have tried other options and none seem to work. Your response to this issue will be highly appreciated.
Last updated: 2024-08-12

Post by cfam on Codesys Control for PLCnext SL, Bus not running ^{CODESYS Forge talk (Post)}
Good day I would appreciate it if you can give me some advice on how to fix my "Bus Not Running Error". I am Using Codesys 3.5 SP20 and Codesys Control PLCnext SL V4.12.0.0. Codesys control was installed on the device and I can log into it but it seems that it does not pick up the PLC or the IO attached (Please see attached Image). The Bus Cycle Task of the AXL F 2152 is set to Main Task and the "Always update Variable" is Enabled on each IO Module. My Main Task interval is set to 100ms and Priority is set to 0. I have tried other options and none seem to work. Your response to this issue will be highly appreciated.
Last updated: 2024-08-12

Post by micik on Reverse bytes in an array ^{CODESYS Forge talk (Post)}
Hello, I'm getting the data in Codesys that is an array of 8 bytes. From this array, I need to foram LREAL number, however, because of different endiannes I need to reverse bytes in this array and then copy to a LREAL variable. For this I'm using a loop and it works OK. I wonder if there is a built in function to do this. I have found CAA Memory library but it has functions like reverse bytes in DWORD. But it seems it doesn't have what I need. https://content.helpme-codesys.com/en/libs/CAA%20Memory/Current/CAA_Memory/Reverse-Bit-Swap-ByteWord-order/ReverseBYTEsInDWORD.html What I need is a function to reverse bytes in an 8 byte array, or something similar.
Last updated: 2024-08-22

Post by micik on Reverse bytes in an array ^{CODESYS Forge talk (Post)}
Hello, I'm getting the data in Codesys that is an array of 8 bytes. From this array, I need to foram LREAL number, however, because of different endiannes I need to reverse bytes in this array and then copy to a LREAL variable. For this I'm using a loop and it works OK. I wonder if there is a built in function to do this. I have found CAA Memory library but it has functions like reverse bytes in DWORD. But it seems it doesn't have what I need. https://content.helpme-codesys.com/en/libs/CAA%20Memory/Current/CAA_Memory/Reverse-Bit-Swap-ByteWord-order/ReverseBYTEsInDWORD.html What I need is a function to reverse bytes in an 8 byte array, or something similar.
Last updated: 2024-08-22

Post by thn-power on How to change OPC NodeId IdentifierType ^{CODESYS Forge talk (Post)}
Hi Yet another OPC UA question. When setting up a OPC server using "Communcation manager" (Symbol set and information model) in Codesys the NodeId is always given as "opaque" type. At least when browsing using UAExpert. Other standard OPC objects use numeric (or string) identifier, but for some reason my variables seems to get opaque/binary type. See attached photo. How can I change this? I can't see that this is a parameter in the CodesysControl.cfg. Can this be specified in the information model nodeset? And is it possible to specify the exact numeric or string NodeId for each instance? And on a related topic, is there a way to export the OPC server nodeId's with variable name so that it can be imported in a OPC Client? The .xml files in the project folder does not seem to contain the NodeId.
Last updated: 2024-09-20

Post by sigurdrb on Codesys and error messages, warnings exceptions etc. ^{CODESYS Forge talk (Post)}
Hi, I tried some different libraries (CmpApp etc.) to find some global variables that I could read out as a variable in the codesys environment. Do any one of you know which libraries are best suited for this, and how I can read it out? My goal is to send messages, warnings etc. to the system that communicates to the PLC. Currently if something goes wrong I need to see the logfiles, or go online with the controller. I think I could save a lot of time if I could read the errors from our user interface that is connected to the PLC by TCP/IP.
Last updated: 2024-11-06

Post by askic on Name Validation of Visualization objects ^{CODESYS Forge talk (Post)}
Hello, In my projects, I'm following this recommendation about the rule names in Codesys https://content.helpme-codesys.com/en/CODESYS%20Development%20System/_cds_rules.html, so I always use backtick identifiers, not only for variables, but also for the object names. However, I have noticed that in the current version of Codesys, when adding Visu object, it is not allowed to used these identifiers in the name. This is very different from all other objects like, folder names, POU names, Variable list names etc. I wonder if there is some hidden settings I can use to enable backtick identifiers in the Visu object names? Attached is a screenshot with the details. Thank you!
Last updated: 2025-01-10

Post by pedegani on "Do you really want to perform" dialog boxes ^{CODESYS Forge talk (Post)}
I have the same annoying problem. The confirmation prompt for every single action appeared recently after an update from CODESYS 3.5 SP20 Patch 3 to Patch4, but I don't think it's due to this. Having to confirm every operation while debugging an application is a considerable waste of time and does not help at all to concentrate on development, not to mention that many times you miss the long-awaited event because you are busy looking for the 'yes' button to resume debugging or force a variable. Does anyone know how to disable the confirmation messages?
Last updated: 2025-02-14

Post by imdatatas on Programmatically change Tappet on a cam ^{CODESYS Forge talk (Post)}
Yes, There is. As explained "Manual creation of CAM structure" on below section. Likewise tappet structure also can be create manual and value of the switching point can be change during IEC program running. https://content.helpme-codesys.com/en/CODESYS%20SoftMotion/_sm_basic_cam_programmatic_creation.html Just create a cam table and define some tapped points as sample for your project. Then on project compile, the created cam tapped data is converted internally into a global variable list. By clicking "Display generated code" in the "cam editor", you can display the automatically created global variables for both cam & tappets. Regards, Imdat
Last updated: 2025-04-02

Post by rossanoparis on Internal Error (ARM): Unsupported conversion! With new version v3.5 SP21 ^{CODESYS Forge talk (Post)}
I have updated CODESYS development tool to the version v3.5 SP21 (64bit) The previous version was v3.5.20.40 Compiling an existing application with the new evelopment tool I get the following error. kunbusiodrvrevpibridge, 1.4.1.0 (kunbus gmbh): IoDrvScanModules [IoDrvRevPiBridge](Line 51, Column 1 (Impl)): Internal Error (ARM): Unsupported conversion! This error was not reported in the previous compiler version and is now highlighted in a third-party library, which I cannot change or modify. The error is due to the following conversion: m_udiError := TO_UDINT(excCode); . The excCode variable is a system type, declared as shown below, and should be converted to a UDINT excCode : __SYSTEM.ExceptionCode; m_udiError: UDINT; . I would appreciate it if someone could provide feedback on this issue.
Last updated: 2025-04-15

Post by kut69 on Retain / Persistent Variables in Codesys for Raspberry Pi ^{CODESYS Forge talk (Post)}
Hi, I am interested in details about the .ret file in the filesystem. I have already a project where the file is used (write on demand, read by start) and I want to share it as 'default input' for test devices using the identical application. Opening the .ret file content in a hex editor (I only use a single string retain var) I asked myself what the meaning of the first 24 bytes is. It neither contains a handle to the application nor a reference to the variable. Is this maybe a timestamp? Or a CRC/checksum? Regards, Thomas
Last updated: 2025-05-19

Post by viksym on How to get the motor scaling value from code ^{CODESYS Forge talk (Post)}
Is there a way to see what value is set as the "Work travel distance per motor rotation" that is set in the Scaling menu of the axis ? I am working on my own homing function block for sensorless (hardstop) homing and I want to make it be universal between different axes with different motor's scaling for distance per rev so I need to know this value from the axis itself. I know I could do it by just creating an input variable for the function block but I'm leaving that option as a last resort.
Last updated: 2025-06-12

Post by hclai on Maximum Array Index Issue ^{CODESYS Forge talk (Post)}
I was trying to use a table object in visualization. I want to dynamically show the valid rows in the table. However, it does not work when there is 1 row. i put the maximum array index to 1. it does not show the 1st row. when i change to 2, it show the second row only. my project with older visualization profile version is working perfectly fine. I did some test and realized that i must use a Row Selection variable to change from 0 to 1. With this change of Row selection, then the row 1 will show up.
Last updated: 2025-06-19

Post by fedex03 on Read Global Variable from an IoT Device ^{CODESYS Forge talk (Post)}
Hello everyone, I am new to the forum, and to programming with CodeSys. I am dealing with IoT device for industry and I should check if a device is able to read/write global variables in an EtherNet/IP Master. Since I do not have an EtherNet/IP PLC, I thought of using CodeSys as a softPLC. I created a program with a set of global variables (GVL) and a task that increments them. I would like to know if I need to enable any options so that the global variables can be read by IoT devices. My device supports Class 2 Class (Explicit Messaging Connection) communication. Thank you in advance for your help.
Last updated: 2025-07-22

Post by timvh on Codesys 3.5.18.60 – Application Loss and Persistent Data Corruption ^{CODESYS Forge talk (Post)}
Which device do you use? Does this have persistent memory (e.g. NVRAM) available? Maybe first ask your PLC vendor about the possibilities and how they advice to use persistent variables? If you have no NVRAM available, CODESYS will store the variables in a file when the device gracefully shuts down. But on an abrupt power failure, this is not possible. If you have no NVRAM and you want to use persistent variables, then consider using a UPS. In this case when the power is lost, the UPS can keep the power on the PLC which then can gracefully shut down. Alternatively use the Persistence Manager to store the variable values in a file e.g. only on change. See: https://content.helpme-codesys.com/en/CODESYS%20Application%20Composer/ac_pm_overview.html
Last updated: 2025-08-26

Post by pernockham on AC Persistence - values are not read from file during start? ^{CODESYS Forge talk (Post)}
I swear I tested this like 20 times yesterday without success. Repeated it today and it works. Maybe the system needed a "real" power reboot? To note. To make a manual edit of a variable I tried some different approaches this is what worked for me. "system/online edited" gvl_var.example_variable REAL:F16#2FFB334H-4 767.7 "manually edited" (with runtime stopped followed by a "cold start" to read from file) gvl_var.example_variable REAL:790.1 (the system will use the manual value but will not set an equivalent "hex" value until next online edit/write cycle)
Last updated: 2025-09-03

Post by durallymax on Persistent Vars ^{CODESYS Forge talk (Post)}
Looking for a better way to manage Persistent Variables. We tend to have local vars in our FBs that need persistence through downloads as the systems are updated/altered on a regular basis. Retain would suffice if we had an easy mechanism to backup and restore like we can with Persistent variables and recipes. Although not having to remember that step with Persistent variables is preferred. We're running into issues with persistent storage capacity (WAGO PFC200) using the Persistent variable list (and adding all instances). It appears there are many ways to handle this, some with recipes, some with files, others with application manager. Is there a solution that exists that is as simple as declaring as Persistent and managing elsewhere? Or do we need to move onto periodically writing CSVs?
Last updated: 2025-09-22

Post by ranadheer on Implementation of IEC-104 ^{CODESYS Forge talk (Post)}
Hi Everyone, As we didn't have client for IEC - 104 - only server server is available , so because of that we are trying to make establish the communication between the external simulator as a Client and codesys itself as a server. We are looking for the variable behavior from CODESYS has to change according to the message triggered by the CLIENT (we are using simulator Application like Redisant). We are able to see the log data as the status of triggering the SCS from Client received to the Log data of the codesys device(attached screen shot of it) and in simulator panel we had set the details to trigger the data from Redisant to Codesys. Current Status: The project builds and runs successfully, but I need guidance on how to connect this to an external IEC-104 simulator for testing and visualization by using demo mode.
Last updated: 2025-10-14

Post by ranadheer on Implementation IEC-104 ^{CODESYS Forge talk (Post)}
Hi Everyone, As we didn't have client for IEC - 104 - only server server is available , so because of that we are trying to make establish the communication between the external simulator as a Client and codesys itself as a server. We are looking for the variable behavior from CODESYS has to change according to the message triggered by the CLIENT (we are using simulator Application like Redisant). We are able to see the log data as the status of triggering the SCS from Client received to the Log data of the codesys device(attached screen shot of it) and in simulator panel we had set the details to trigger the data from Redisant to Codesys. Current Status: The project builds and runs successfully, but I need guidance on how to connect this to an external IEC-104 simulator for testing and visualization by using demo mode.
Last updated: 2025-10-14

Post by macros8 on Translation - How to get text as reference in Frames translated? ^{CODESYS Forge talk (Post)}
Hi, thanks for the link. Maybe I create elements in incorrect way. I always use Interface Editor to create variables which are used inside element (see pics). After that I place element in my visu and use Reference property to link variable or set the value. In that case the value of string is not transferred to general text list for translation as I mentioned before. Do I have to all properties which influence behavior of my element create in Frame configuration instead? What´s the difference to the Interface editor? Thanks a lot. M.
Last updated: 2024-01-02

Post by matt-s on HMI Pushbutton/Move Instruction ^{CODESYS Forge talk (Post)}
I am having an issue where the manual start/stop push buttons on the HMI are supposed to take the pumps/blowers out of auto. The logic I have attached works for the pumps, but not the blower. From what I can tell it is the exact same logic, but it is not writing a 0 to the Auto PB variable. Attached is the logic, cross reference list to show nothing else is writing to it, and the HMI screen. Any help? Am I missing something? I am using a Groov Epic PR1, my software version is 3.5 SP19 Patch 5 32 Bit.
Last updated: 2024-01-25

Post by matthew on New Ladder Diagram conversion does not work due to missing features ^{CODESYS Forge talk (Post)}
Hi It looks like in the new ladder there is no way to remove unused FB call parameters or update the function block? It's quite often where you have a function block with multiple uses and not all the parameters are required. Need the ability to leave an input/output blank without getting an compile error Expression expected instead of '' Also double clicking on the FB no longer opens the underlying FB code and view what it was doing online. Dragging and dropping a variable does not work, only using the selection works. Will these be available in the V1.0 release or just best to stick to the old ladder until it's available? Thanks
Last updated: 2024-01-28

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