Post by pernockham on Gateway in China - "Gateway not connected" ^{CODESYS Forge talk (Post)}
I think I understand my problem. They are most probably related to configuration of the network. When I use DHCP for the unit to my router it all works. However when using static IP I have not managed to reach functioning state. Trying to replicate the situation on my desk. Having a static IP on the "debian host" and a connection to my computer which then routes traffic on to internet. I have entered settings for gateway and netmask. I can ping from my "debian plc host" to internet and also do "curl google.com" so traffic seems to find its way through and back, still "Automation server" will not find the gateway. Any hints how a manual configuration should be done? Is it possibly a "firewall" issue of my "normal router"? Thanks for any help! Per
Last updated: 2026-01-27

Post by madskaizer on Task Priority Documentation? ^{CODESYS Forge talk (Post)}
Hi All I was watching the Wago PFC300 webinar ( https://www.wago.com/global/lp-thank-you-onlineseminar-pfc-300 ), and the presenters comment about priority 1 being way above the Ethernet task priority, so that a priority 1 PLC program can actually loose SCADA connection, made me try to round up some hard evidence on Codesys Priorities. I find there is very little information on "correct" task priority configuration. There is a lot of different hardware manufacturers, using Codesys Runtime, that has different descriptions in their manuals on how to set up priority. https://doku.amk-motion.com/en/Subsystems/PDK_202975_A-Serie_en/Content/Projekt/AMKAMAC/PDK_202975_A4-A5_Produktbeschreibung/Funktionalitaet/PLC-Programming/PLC%20Tasks.htm?TocPath=PLC-Programming%7C_____7 https://product-help.schneider-electric.com/Machine%20Expert/V1.1/en/SoMProg/index.htm?#t=SoMProg%2FTask_Editor%2FTask_Editor-7.htm&rhsearch=priority&rhhlterm=priority&rhsyns=%20&SUBSTRSRCH=1 https://content.helpme-codesys.com/en/CODESYS%20Development%20System/_cds_f_task_configuration.html So my questions :) 1) If there is only 1 PLC_PRG task, does priority matter? 2) What is the priority of Ethernet / communication, if nothing is entered? 3) What is the priority of Codesys OPC UA server? 4) Some users here on forge mentions that Wago PLC programs should run as priority 11, but where does this recommendation origin from? 5) What are you recommendations for a relatively slow process, like building automation? It uses OPC UA for communication to SCADA, maybe some MODBUS-RTU and MODBUS-TCP, usually around 100 I/O, been running with everything in a single task at priority 1, 50-100ms cycle time. Some controllers have separate MODBUS tasks, but doesn't seem like a big difference. How would you recommend splitting up communication, IO fieldbus and programs into differently prioritized tasks? I know its a complex matter and all about my application, but I really miss there was just some kind of guidance in the documentations and with all new standard Codesys programs having priority 1 as default, makes it seem less important, than it really is.
Last updated: 2025-08-11

Post by mozed on Connection to device closed ^{CODESYS Forge talk (Post)}
Hello I am using an OpusA3 with version 3.5 SP17 Patch 3 as part of a project. I had no real problem before I encountered a problem that blocked me. The detection of the OpusA3 from Codesys is done correctly. The gateway is well configured and if I ping the gateway or the OpusA3 I receive the response correctly. The problem is that when I try to connect, the Opus screen freezes and a few moments later Codesys displays an error message ("connection to device closed"). I tried to change PC, to update the runtime, to change OpusA3 but the problem remains the same. I'm a little lost knowing that before it worked without problem. I went back to a previous version of the project (where it worked correctly) but the message still appears. Do you have any clues to solve the problem? Sincerely,
Last updated: 2023-08-23

Post by caliberbishop on Having trouble using the Web Client SL library ^{CODESYS Forge talk (Post)}
Hello, I'm trying to use the Web Client SL library, I installed it in the IDE (did not purchase a license yet, as this is still a proof of concept so demo mode is good enough) and added it to the library manager. However, when trying to define a FB of the type WebClient I get a "Identifier 'WebClient' not defined" error message, setting the type to Web_Client_SL.WebClient did not work as well. Opening the example project the FBs defined there give the same error message. From the problem in the example project I deduce this is not a syntax problem, so maybe a license problem, but there should be a working demo mode, so what am I missing? IDE v 3.5.21.30 Library v 1.12.0.0 Thanks
Last updated: 2025-10-04

Post by manuknecht on Using SMC_MOVTYP.INITPOS without specifying the start position ^{CODESYS Forge talk (Post)}
I am using the object SMC_GEOINFO to generate a trajectory and move a system accordingly using the SMC_INTERPOLATOR function block similar to the sample project CNC10_DynamicPath.project. According to the documentation, the movement type INITPOS does not require a start position in the SMC_GEOINFO object, which is confirmed in the documentation of the SMC_GEOINFO object. When using the movement type INITPOS however, the motion will still start from the starting point defined in the SMC_GEOINFO object (0,0,0 if not specified otherwise). Does someone know how to resolve this or is there an example project that makes use of the INITPOS movement type without specifying the starting point? Thanks in advance!
Last updated: 2023-12-15

Post by imdatatas on MC_MoveAbsolute: C0138: No matching 'FB_Init' method found for instantiation of SMC_MoveAbsRelPerformerImpl [ERROR] ^{CODESYS Forge talk (Post)}
Dear @gseidel, Thank you for your reply. The exact version of Codesys and its compiler was 3.5.21.20. The compiler version was fixed and could not be changed in project settings. Since I couldn't continue due to this compilation error, I temporarily overcame this issue as follows. -- I completely uninstalled Codesys 3.5.21.20 and completely deleted the Codesys folder in the C:\ProgramData folder. -- I restarted my computer and installed Codesys 3.5.19.70. -- I updated the Codesys Installer and all its add-ons to the latest versions. -- The project that was giving me the compilation error I mentioned before is now open with Codesys 3.5.19.70, compiled it, and successfully downloaded it on the device. -- I haven't encountered the same problem anymore. I think this issue is related to SP21 and its compiler. Frankly, I'd expect a project created with an older version to compile without errors after opening it with the latest Codesys version and updating all libraries. Regards, imdatatas
Last updated: 2025-09-26

Post by hyys12 on Help understanding analog in-/outputs ^{CODESYS Forge talk (Post)}
Hello. I am currently working on a WAGO PLC, where I am trying to wrap my head around how the analog inputs and outputs work in codesys. I have looked far and wide on the internet, for a general introduction to the whole concept, but I have not had any luck with finding anything that helped me understand it better. The whole goal is for me to be able to read an analog input from a temperature sensor, as well as using an analog output, to control a frequency inverter. I know these have nothing to do with each other, but that is all I have on hand right now. I am trying to program this using Ladder Diagram. The only thing is, that every video/guide I have seen/read using LD, just adds a whole lot of function blocks, to do all kinds of stuff they don't explain. My general question is, how would one go ahead and read the analog input, as well as transmit an analog output? Is there some kind of specific function block I would have to use for this, or some great video I can watch, to understand the inner workings. Is it somehow possible to see the values the PLC recieved/sends? Regards.
Last updated: 2024-12-11

Post by simone on Collapse all ^{CODESYS Forge talk (Post)}
Hi, I'm wondering if it exist a button or a keyboard shortcut (much much better) for "collapse all" the open folder on a codesys project. It would really be nice to have. Also: Are there some options or configuration for set a default zoom for the different editor (or even one global), for example I would like to have 100% on ST, LD editor and have 80% on Visualization Editor; and also have a button to set all the zooms to default, now it seems that every file mantain the one previously set. I'm working with the 3.5.20.10 right now Thanks!
Last updated: 2024-11-21

Post by hemuv on Dialog Open ^{CODESYS Forge talk (Post)}
I'm programming an HMI for a machine. I want to log all the parameter's changes (used text field for displaying and changing) for particular User levels. Created a Numpad and want to log oldvalue and Newvalue on 'ok' Button press. To retrieve the oldvalue, i check if the dialogue opened is my Numpad, Then I retrieve the dialogue interface via GetDialogInterface(ADR(myNumpad)) --> numpadData.stVariableValue which contain my oldvalue and save it locally. Problem is sometimes i retrieve the data and sometimes not. Also observed when Numpad Dialogue is Opened, VisuDlgUtil_IsDialogOpen returns False in some cycles.Attached you will find my Project. please let me know what went wrong or if there is a better approach to collect old and New Value of a textfield. Thank you.
Last updated: 2025-03-26

Post by i-campbell on What does CODESYS expect to do when I get such an error message ^{CODESYS Forge talk (Post)}
you need to get the addons that the person that programmed it used. I always store an .installation-config file alongside the project. If you have lost that, then it gets a bit of a headache: I think even with SP18 you can hit yes to open it anyway, and it will suggest which addons it thinks are missing, if you double click the yellow "missing-addons" in the status bar. If you know you have the right addons, you can do a "Save As.." and it will write your current addon list to the file, and you wont get the error next time.
Last updated: 2024-01-08

Post by installwhat on C0077 on one machine but not another ^{CODESYS Forge talk (Post)}
I have a version of codesys 3.5.16 on my local machine and a vm. The local machine has loads of codesys versions and libraries installed etc. I can open the FPosCR_Example_Project_SP16_patch1 project on my vm without any errors. On the local machine I get the error C0077: unknown type IoDrvEthercatLib.ETC_CO_SdoWrite. I can, on the local machine, declare a var of type IoDrvEthercatLib.ETC_CO_SdoWrite and include it in the code without adding an extra error. The problem only seems to affect the library. This is seems more an issue with my codesys set up rather than something with festo. I would like to know the possible causes. I understand most of the library manager features but it's not clear how to find the cause. Thanks
Last updated: 2024-06-11

Post by janderson on Ethercat scan for devices not picking up EL7041 as a softmotion axis ^{CODESYS Forge talk (Post)}
it appears that the different revisions have different PDOs. I am currently trying to use the rev25. I have tried to use the rev24 (the device repository entry not from 'scan for devices') and i keep getting 'invalid output mapping' or 'invalid input mapping' in the ethercat log. I cant even get the bus to run from the device description that comes from 'scan for devices'...
Last updated: 2023-09-18

Post by janderson on Ethercat scan for devices not picking up EL7041 as a softmotion axis ^{CODESYS Forge talk (Post)}
it appears that the different revisions have different PDOs. I am currently trying to use the rev25. I have tried to use the rev24 (the device repository entry not from 'scan for devices') and i keep getting 'invalid output mapping' or 'invalid input mapping' in the ethercat log. I cant even get the bus to run from the device description that comes from 'scan for devices'...
Last updated: 2023-09-18

Post by liamb on Converting CANbus to Decimal from signed 2's complement ^{CODESYS Forge talk (Post)}
I need to combine two 8 bit CANbus messages to 16 bits signed int then convert to decimal Decimal from signed 2's complement. I've been using the below code to read for new messages, combine them then assign them to a variable What is the best way to do this for from signed 2's complement? fbRxMessage351(Data := RxMessage351Data); IF fbRxMessage351.NewMessage THEN ChargeVoltage := (WORD_TO_REAL((RxMessage351Data[0]) + ((RxMessage351Data[1]) * 256))) * 0.1; END_IF
Last updated: 2024-08-16

Post by timvh on Stack overflow with really simple function ^{CODESYS Forge talk (Post)}
You have declared the function block in a function and call the instance also from a function. This is not correct, because a function is initialised with every call. The http client function block should be declared as Global Variable if you want to cal it from a Function, but probably it is better to declare it in a Program and also call the instance of the http function block from the same Program.... The variables of a Program are not initialised with each call.
Last updated: 2024-09-20

Post by dogulas on Removing a symbol from the IEC Symbols Editor grid ^{CODESYS Forge talk (Post)}
gatto, That works. Thanks. Typically I use my mouse more than my keyboard. That's why I was looking for a delete option from the right-click context menu or a delete button on a toolbar at the top. It never occured to me to use the keyboard. It might be a little more user friendly if they allowed a mouse wise ability to remove a line from the grid as well as the DEL key. Just a suggestion. Thanks for your help.
Last updated: 2025-02-13

Post by sumit on Not able to see input data coming from eip adapter on codesys ^{CODESYS Forge talk (Post)}
Hello there, I have an eip adapter running (remotely) that is sending data back to eip scanner (running on codesys). I can send data from scanner (codesys) to the adapter but not getting the data back from the adapter. I have verified the incoming data on wireshark but I don't see this data in the codesys. I have tried local variable mapping and global variable mapping not variable values just stays at 0. Please guide.
Last updated: 2024-02-29

Post by ppanchal on Add a dynamic text on One Visualization from another ^{CODESYS Forge talk (Post)}
I've created a TitleBar Visualization in which I have "Logo" on the Left corner, "Screen Name" in the center and Time/ date on the right corner. I've also created a 'Menu" visualization that slides out from left to right. I have TitleBar and Menu Visualizations in the MainScreen (3rd Visualization). I want to have "Screen Name" automatically updated on TitleBar Visualization based on Menu item selected from the "Menu" visualization. Can anyone advise how can I achive this? TIA
Last updated: 2025-11-18

Post by akrawczyk on Dynamically enabling/disabling Modbus slave devices in runtime (performance issue with timeouts) ^{CODESYS Forge talk (Post)}
Hi everyone, I'm working on a CODESYS-based project running on a Weintek cMT2078X HMI with a built-in CODESYS runtime. The system communicates with multiple Modbus RTU slave devices, arranged in a cascade. The number of connected units can vary between 2 and 8, depending on the installation. Each slave has 17 Modbus channels, which are polled cyclically every 5 seconds. The issue is that when fewer devices are physically connected (e.g. only 3 out of 8), the Modbus master still attempts to communicate with all configured slaves. This leads to massive delays due to timeouts (currently 200ms per channel). For one disconnected device, that’s: 17 × 200ms = 3.4 seconds of delay per polling cycle, and this quickly multiplies with each additional missing slave. This behavior significantly degrades the system's performance and responsiveness. We attempted a workaround where we tried to trigger polling based on a variable in the PLC program, but this caused instability and even led to hardware hangs/freezes on the cMT2078X – likely due to clashes in how the Modbus polling engine and program logic interact at runtime. My main questions are: Is there a way in CODESYS to dynamically enable/disable Modbus slave devices at runtime, using a BOOL or INT variable (e.g. indicating number of active slaves)? Can devices or channels be conditionally polled or temporarily disabled without removing them from the device tree? Are there any best practices or examples for handling variable numbers of Modbus slaves in scalable systems like this? Would splitting communication across tasks or interfaces help reduce the impact of timeouts? Any advice, documentation references, or architectural suggestions would be extremely helpful. I'm looking for a robust way to dynamically scale slave polling without degrading system stability or performance. Thanks in advance!
Last updated: 2025-08-11

Post by rcaponi on Codesys Control RTE V3. Remote Control ^{CODESYS Forge talk (Post)}
Hello, I would like to have, if possible, some clarification on this function. That is, I would like to understand if it is useful for managing, fom my development PC, the RTE runtime executed on a remote control. This is what the help says: Remote PLC: Opens the Remote Configuration dialog. By enabling or disabling the Control remote PC, not local option, you determine whether a PLC is used that is on a remote or local PC. Accordingly, the menu commands Start PLC, Stop PLC, and PLC Configuration refer to the local PC or a PC reached on the network. For the remote PC, specify the Target PC address, Port number, and a Timeout value (in ms) for the connection (Remote Timeout [ms]). But does this mean that I also need to install the RTE runtime on my development PC? Is it possible to have some more information? Best regards Roberto Caponi
Last updated: 2023-09-22

Post by kunal-pinetics on USB Communication for IP Configuration & Application Update – STM32H Series PLC ^{CODESYS Forge talk (Post)}
Hello everyone, I am currently working on a PLC device based on the STM32H series MCU, running CODESYS. At the moment, I can: Change the Ethernet IP address Update/download the PLC application via Ethernet without any issues. However, I would like to implement the same functionality over USB (or Serial via USB) instead of Ethernet. My goals are: Change the device’s Ethernet IP address via USB Download/update the PLC application via USB communication Possibly use USB as a service/programming interface The hardware platform is based on STM32H series, and I am looking for guidance on: Whether CODESYS supports USB device communication for runtime download If a custom USB CDC (Virtual COM Port) implementation is required Whether a specific CODESYS runtime configuration is needed If a bootloader approach is recommended for application updates via USB If anyone has experience implementing USB communication for runtime download or device configuration on an STM32-based PLC, I would really appreciate your guidance. Thank you in advance for your help.
Last updated: 2026-02-26

Post by patrik on Wish: CODESYSControl.cfg - again ^{CODESYS Forge talk (Post)}
Really good post. I hope that it gets seen by CoDeSys staff. I often find the documentation lacking when it comes to using CoDeSys in more complex ways. If using standard "basic PLC functionality", then it's fine and functions are documented in a sufficient way. Once you go outside of that bubble then I find the documentation not enough. CODESYSControl.cfg is a good example of this. And why isn't more of this integrated in the IDE. like changing port of the webserver. Why is it hidden in this file and not accessible through the IDE. It feels like a layer of complexity purposely left in so you don't change it if you don't know what you are doing. Like the argument is if you have the know-how to find the file you have the know-how to edit it. I find the documentation lacking when it comes to more complex libraries too. Like the element collections library. there is parameters I still don't quite know what they do. I can't find any documentation about them. There is an example project to download from CoDeSys so you can see how you are supposed to set your factories up. I leave some parameters like it is in the example. Should I? I don't know. Does it work. Yes. But I could perhaps create memory leaks if I get something wrong and I don't see that until way later. In the create method of your element factory you have a function called __vfinit and you just have to accept that it works. Why can't I get insight in what it does through documentation? Don't CoDeSys want us to know how these work so we can't use them to accidentally break something? I find the error logging lacking too. I've had the CoDeSys service crash but it doesn't say why. I've seen windows noticing the crash but no error code was sent or error message. Also in my current issue where the application fails to start after power outage. I can see in the log that it fails to load retain in the application as one log entry and application failing to start as another. But why? Why does loading the retain fail? give me more information! Is it just a skill issue with me? I don't know. If it is then I'd still want CoDeSys to step up their game when it comes to documentation. I'm sorry if a lot of frustration comes though in this post. I really like the product and what I can do with it compared to other PLC brands.
Last updated: 2024-11-21

Post by cfam on Codesys Control for PLCnext (PLC - AXL F 2152) ^{CODESYS Forge talk (Post)}
Good day All I would like to share some information on this site for the Codesys team as well for the future members using Codesys Control for PLCnext if it is allowed. I hope that i Post it in the correct spot. Subject: Codesys, Codesys Control for PLCnext Objective: Using the following Phoenix components to built a PLC Rack and run it on Codesys: Hardware and Software used 1. 2404267, AXC F 2152 - Controller 2. 1088136, AXL F BP SE6 - Module carrier 3. 1088129, AXL SE DO16/1 - Digital module 4. 1337224, AXL SE PD16 GND - Potential distributors 5. 1088127, AXL SE DI16/1 - Digital module 6. 1337223, AXL SE PD16 24V - Potential distributors 7. 1088123, AXL SE AO4 I 4-20 - Analog module 8. 1088134, AXL SE SC-A - Cover 9. Codesys v3.5 SP19 Patch 4 10. Codesys Control for PLCnext V4.10.0.0 Process: Firstly I built the Rack according to the Phoenix Project+ Software tool. Where I rebuilt it onto my test bench . I used the PLCnext Engineer IDE from Phoenix and all Communications where up and running and my PLC program executed successfully. THEN I tried the same PLC Layout with Codesys and Codesys Control for PLCnext. It was not successful and gave me the "Error: Local Bus not Running". I searched the web for answers but was unsuccessful in finding a solution. So I tried to change my configuration and found that the following Modules COULD NOT be recognized by Codesys Control. The result was that the Local Bus Failed to run. 1337224, AXL SE PD16 GND - Potential distributors 1337223, AXL SE PD16 24V - Potential distributors Example 1, Resulted in "Error: Local Bus Not Running": Module carrier slot 1: 1088129, AXL SE DO16/1 - Digital module Module carrier slot 2: 1337224, AXL SE PD16 GND - Potential distributors Module carrier slot 3: 1088127, AXL SE DI16/1 - Digital module Module carrier slot 4: 1337223, AXL SE PD16 24V - Potential distributors Module carrier slot 5: 1088123, AXL SE AO4 I 4-20 - Analog module Module carrier slot 6: 1088134, AXL SE SC-A - Cover Example 2, Result "Successful": Module carrier slot 1: 1088129, AXL SE DO16/1 - Digital module Module carrier slot 2: 1088127, AXL SE DI16/1 - Digital module Module carrier slot 3: 1088123, AXL SE AO4 I 4-20 - Analog module Module carrier slot 4: 1088134, AXL SE SC-A - Cover Module carrier slot 5: 1088134, AXL SE SC-A - Cover Module carrier slot 6: 1088134, AXL SE SC-A - Cover Result: Codesys or Codesys Control for PLCnext, has a PROBLEM to identify the following Modules. 1. AXL SE PD16 24V - Potential distributors 2. AXL SE PD16 GND - Potential distributors Hope that this information could be useful in future. Best regards Jaco Pretorius
Last updated: 2023-12-06

Post by paulorb on STRUCT AT %MW1000 ^{CODESYS Forge talk (Post)}
Hi I am trying to use STRUCT to parse commands from Modbus/TCP, Modbus client will fill the bytes related to a specific command (type, parameters), then PLC (Codesys) will access the command parameters. A STRUCT will simplify a lot the process of parsing the data, so I don't need to parse byte per byte, address will be mapped to a struct and I can use it for parsing the data. From what I understood, the compiler does not allow me to specify the location of the struct for a %MW register. VAR_COMMAND AT %MW1002: structGenericModbusCommand; This will throw: Bad declaration, use '%ML' for 'structGenericModbusCommand' variable But If I change it to %ML, when you go online you see that it is actually allocating the struct in another memory address. When we go online, on GVL we can see: VAR_COMMAND. structGenericModbusCommand %ML1002 commandType COMMANDTYPE %MB8016 ... %MB8020 I am not specifying a pointer or a reference it is a struct type, why is it mapping to a %MW location (random one). How can I control where it is mapping to? I need a consistent way to map STRUCT to specific modbus address. Is it possible? Thanks, Paulo Note I am using a Codesys OEM: Schneider Machine Expert Logic Builder (M241)
Last updated: 2024-08-13

Post by gmau on RS232 Communication in CODESYS Control RTE V3 ^{CODESYS Forge talk (Post)}
Hello, I would like to implement RS232 communication into CODESYS Control RTE V3. I was writing the program testing it on CODESYS Control Win V3, where it worked fine. When I changed it to RTE, the communication was on, but I cannot send the data between PLC and scale - there is no or little response from scale - mostly one time receive and that is it. On Win V3 it was working fine. I read that I am supposed to configure CODESYSControl file for a proper communication using RTE, but even after that I can not get a stable and working communication. I am attaching my CODESYSControl and CODESYSControlUser data below, as well as I am sending the code from communication function. The communication should be through COM1 port of PC. CODESYS Version: CODESYS V3.5 SP21 + (64-bit) Runtime + Version: CODESYS Control RTE V3 Version 3.5.21.0 / CODESYS Gateway V3 - x64 Version 2.5.21.0 I would be much gratefull for any help. Sincerely,
Last updated: 2025-07-16

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