Post by aris on Modbus write via FB failure ^{CODESYS Forge talk (Post)}
Hi all, I am using CoDeSys V3.5 and a soft controller Win V3x64. I am trying to read a modbus slave via Function Blocks and not via the channels of the hardware tree for the Slave. I created some requests of type ModbusRequest and I notice that I can read Input Registers and Coils but I can not write Holding Registers and Coils. I am using the library IoDrvModbusTCP 4.1.0.0. When i just use a single modbus request with FC06 (or FC16), there is no request sent to the slave and although the xExecute takes its true value from a pulse of 2 seconds duration, I take almost every 3 minutes an error "TCP_COMMUNICATION_ERROR - 16#A5 - TCP Port. error. Request was not sent". My code is ok because if i change the function code for reading registers, everything works fine. Did anyone have this issue in the past? Thank you in advance.
Last updated: 2025-11-06

Post by fajean on Issue with library updates ^{CODESYS Forge talk (Post)}
We make heavy use of internally developed libraries, which are often nested on multiple levels. I routinely work simultaneously on several libraries along with a project that use them. I make changes to a library and immediately perform a download (online or otherwise) in the project. For the longest time, we had zero issue with this. But starting a good while back, with 3.5 SP19 I think, CODESYS started not noticing library updates in other instances most of the time. When the update is missed, the project sees no need to update the code, and any download ignores the new code. A "Clean all" does not solve the issue. But if I close and then re-open the project, then the new version is noticed and the download works. The other solution is saving the library to the registry multiple times (say, 20-30 times, less if lucky), and then at some point the project notices the changed library. I am now on SP21, and it is still not fixed. This is driving me mad, any tasks probably takes me double the time or more due to this problem. My colleague has the same problem on a separate computer. Is this a known issue? Is there a setting somewhere that changes how updates are checked? Thanks for any help!
Last updated: 2026-02-13

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 murdemon on CNC Jumps G20 - SMC_NCInterpreter and long time to process ^{CODESYS Forge talk (Post)}
Best way.. in CNC program before G20 jump, set G75. And for fbCheckVel execute if fbInterpreter.bWorking AND fbInterpreter.bLastObjectWasAdministrative; and same for Interpolator. " ..... dumm := fbInterpreter.bWorking AND fbInterpreter.bLastObjectWasAdministrative; //Check velociteses. fbCheckVel(bExecute := (fbInterpreter.bDone or) dumm, bAbort := gCNC.bCycleStop, poqDataIn := fbInterpreter.poqDataOut); "
Last updated: 2024-08-03

Post by martinlithlith on Relay board / relays for raspberry pi 3 b+ ^{CODESYS Forge talk (Post)}
hi! im planning a project on a raspberry with Codesys. For this I'll need a number of relays to control heating and fans, all a max of 24v and about 2a. How would i know if the board / relays i buy will be working with Codesys? Does every hat work or does it need a library/driver? is there a list of drivers/libraries created? as this is a hobby project all tips on a relay board or single boards that works with codesys and not to expensive are very welcome.
Last updated: 2023-09-03

Post by transmin01 on CANbus issue ^{CODESYS Forge talk (Post)}
Update: This initial issue was when using a Linux target PLC. Since then I have created a Win10 target PC and the Codesys software reported an issue associated with the device version (see attached). I am assuming this is an incompatibility with the xml file from the manufacturer and the firmware version on the module and I am chasing this up with Beckhoff. Question is, why would this not report with a Linux target?
Last updated: 2023-09-14

Post by tehthoams on Library Search not working ^{CODESYS Forge talk (Post)}
Hello All! Having a strange issue. When adding a library, I'm unable to search. Each time a window pops up 'creating the search index' and then has 0 results. I have the same behavior when using the library repository and pressing the 'Find' button. I wonder if there is a way to reset or fix this issue? It is making it very difficult to search and find proper libraries to add to my project. Much appreciated.
Last updated: 2023-10-17

Post by tcarlbom on codesys sp20 opcua not working ^{CODESYS Forge talk (Post)}
hi, anyone else having trouble with opc ua in codesys sp20? i get Error 'BadIdentityTokenInvalid' was returned during ActivateSession i have tried both windows x64 runtime and linux runtime. i have created a completely new codesys project for this. in each of them i have only added the symbol configuration and selected one tag. i have tried several opc ua client, like ua expert, nodejs and python. all return Error 'BadIdentityTokenInvalid' was returned during ActivateSession so the problem must be the opc ua server.
Last updated: 2024-07-03

Post by schweizer on Position und Größe optimal anpassen (Container.Height - Visu.Height) funktioniert nicht. ^{CODESYS Forge talk (Post)}
Hello forum Does anyone have experience with optimally adjusting the position and size of the visualization elements? For us, the adjustment on the x-axis works in Codesys 3.5 SP20 with (Container.Width - Visu.Width). However, the y-axis is not affected with (Container.Height - Visu.Height). We implemented this according to the example from Codesys "Optimally adjust position and size" and had no success. Thank you very much for your help.
Last updated: 2024-07-29

Post by ivanh on kepware minimun privilege ^{CODESYS Forge talk (Post)}
Hello everyone, I’m integrating Codesys with Kepserver using the Kepware driver for Codesys, and I need to configure a user account with the minimum necessary privileges to read and write to the tags on the PLC, without using the internal OPC UA server of Codesys. However, despite not assigning the Modify permission, Kepware still allows writing to the tags. What are the minimum required permissions to ensure that writing is only allowed when necessary, and how can I prevent other permissions from being overridden? Any guidance would be greatly appreciated.
Last updated: 2024-08-12

Post by stribor on Passing properties as VAR_IN_OUT variables. ^{CODESYS Forge talk (Post)}
I am designing a custom slider object and i ran into a problem when i want to use properties with it. I can update the basic variables if i have a slider variable defined as VAR_IN_OUT, but it does not work with properties. How can i achieve same functionality that some basic objects have (for example basic Slider that comes withing the codesys libraries) such that i can pass both variables and properties to it and they can be modified within the object? I am using Codesys V3.5 SP20 Patch 5.
Last updated: 2025-03-01

Post by nz-dave on ethercat softmotion axis error ^{CODESYS Forge talk (Post)}
Hi all I'm having a little trouble get my axis to work. i can turn them off and on. i can run each servo manually inputting directly to the mapping address. as soon as i try to use any FB's like jog etc my servos wont move and error out. so far I've had error "SMC_ERROR.SMC_DI-POSITIONLAGERROR" and another one about not calling a fb. cheers. in the attachment I have just jogged X_Axis with the MC_JOG FB
Last updated: 2025-03-10

Post by eschwellinger on Changed Device of Rapberry Pi to MC SL instead of standard SL and cannot connect anymore ^{CODESYS Forge talk (Post)}
1) https://store.codesys.com/en/codesys-control-for-raspberry-pi-sl.html -> SL: Restrictions The combination of Raspberry Pi and a CODESYS Runtime is for private use, test and teaching purposes. Commercial use is not permitted. 2) you could switch between them by /etc/codesyscontrol/CODESYSControl_User.cfg [CmpRasPi] Architecture=armv7l for MC: armv7l for SC: armv6l for 64Bit: aarch64 or in the Deploytool:
Last updated: 2025-08-06

Post by reinier-geers on CAnopen stack ^{CODESYS Forge talk (Post)}
Ive got a project with 6 devices . Version 3.5.9.2 Now i change one to a other device 3.5.20.40 So i update the project to V3.5.20.4 Now i have a lot off faults in the canopendevices . Somehowe the first has no problem and seems that the canopenstackts stays in V3.5.9.2 the others in V4.2.0.0 But i cant put it back to 3.5.9.2 WHY ? And how can now witch one i can update and witch one not ?
Last updated: 2025-09-22

Post by reinier-geers on CAnopen stack ^{CODESYS Forge talk (Post)}
Ive got a project with 6 devices . Version 3.5.9.2 Now i change one to a other device 3.5.20.40 So i update the project to V3.5.20.4 Now i have a lot off faults in the canopendevices . Somehowe the first has no problem and seems that the canopenstackts stays in V3.5.9.2 the others in V4.2.0.0 But i cant put it back to 3.5.9.2 WHY ? And how can now witch one i can update and witch one not ?
Last updated: 2025-09-22

Post by felipemsgarcia on Edge Gateway online, but PLC is not online ^{CODESYS Forge talk (Post)}
Hello, I couldn't figure what/where the issue was, so I deleted everything from automation server and reinstalled the edge gateway and did the process again. It worked for about a month and then it stopped working again. It presents the same symptom, edge gateway is online but I can't connect to the PLC. Any idea of what could be the issue? Thank you!
Last updated: 2024-01-09

Post by john-martin on Control SL Extension Package doubts ^{CODESYS Forge talk (Post)}
Hello everybody, I'm trying to understand the SL control extension package, more specifically, the external IODriver example, because C integration is very easy and I just made my first C component successfully. Ther External IODriver has no documentation and it's not clear how to proceed. Furthermore, there is no information on how to modify the device descriptor, which is necessary to import the device into the Codesys repository. Any advice ? Thank you in advance and best regards.
Last updated: 2024-02-28

Post by dominggus on Recipe Manager - RecipeManCommands, load & write wrong values, Bug? ^{CODESYS Forge talk (Post)}
I still have the same problem even when updating to CODESYS Recipes 4.3.0.0. My scenario: I'm trying to save/load an array of structs using the Visu: - Execute Command > "SaveRecipeAs" works properly - Execute Command > "LoadWriteRecipe" works not entirely: the structs of array[6] and array[7] should have been empty but were duplicates of array[4] and array[5]... the struct contains 26 variables and the array's length is 30.. Maybe there is a upper limit on recipe variable count?
Last updated: 2024-03-02

Post by riccardo on Web Browser special tools errors ^{CODESYS Forge talk (Post)}
Nano goodmorning and thanks for the reaply, the links I have to manage are links as the following: https://192.168.1.101/u-os-app-codesys/application/visualization/webvisu.htm I saw that with Wikipedia or other web sites the tool works but not the link above. "google and some other providers, prevent from using as iframe and similar injections." The goal I'm pursuing is to display remote graphical user interfaces from a local graphical user interface over a local network. thanks in advance, Riccardo
Last updated: 2024-03-06

Post by miodusy on File transfer via visu and codesys automation server ^{CODESYS Forge talk (Post)}
I have a problem with the file transfer library. Namely, it does not work via the codesys server. (error 5; overtime, and visualization resets). They operate mostly in local chains. I tested different browsers and VPN from the router. It works everywhere, except through access from the codesys automation server. The client, having many machines under one account, prefers to keep it that way rather than use an individual VPN just to download a backup. Does anyone have an idea what the problem is? Sylwester M.
Last updated: 2024-03-07

Post by andy-yemm on Assertion Failed ^{CODESYS Forge talk (Post)}
I had similar assertion failed error messages today. I am fairly new to Codesys. I tried using SFC for the first time, I usually use ST. Anyway I had errors in some of my transitions. I copied and pasted transition code and forgot to change the target of the code. I started getting lots of the assertion errors but now I have sorted out the problems and it compiles OK the assertion error messages seem to have stopped. There do not seem to be any other responses to your post, did you resolve your problem?
Last updated: 2024-03-19

Post by wind-11 on Problem with simulation Modbus ^{CODESYS Forge talk (Post)}
Hello everyone, I encountered a problem in the simulation while working. In a test project we set up a Modbus connection. We wanted to simulate this with test values. The connection also worked, but unfortunately the values are frozen and do not report any “current data”. (Picture attached) Since these are my first points of contact with Codesys and my colleague continues to work elsewhere, I was hoping that someone here might have an idea. Kind regards and thanks in advance.
Last updated: 2024-03-22

Post by rossanoparis on RevPi CONNECT+, CODESYS, EtherCAT master "Filedbus lost synchronicity" ^{CODESYS Forge talk (Post)}
Hello @rmaas I assume, you've already verified and tuned everything regarding the EtherCAT network. In my case the problem was due to a wrong core assignement. I suggest to not use the core #0 for your EtherCAT task. The OS realtime patch, which is present on RevPi OS, uses the core #0 for its porpouses and it mustn't be used by any other task which requires realtime and deterministic features. regards Rossano
Last updated: 2024-04-11

Post by eschwellinger on License problem gateway ^{CODESYS Forge talk (Post)}
I just try to help. Anyway it is a big difference if a Store SL runtime or an oem plc and licence is used. These licenses need to be activated on plc side - so you have dependencies to the version (CODESYS and Runtime Version) Did you ever ask Epis out for this situation? They should know which license fit to their device. Even they should know if the device is capable for Softmotion and see the requiremnts in the CODESYS store: Runtime 4.9.0.0 - how should this work with Epis 3.5.16.x? Anyway refund is not a problem.
Last updated: 2024-04-26

Post by plunje on Sensor not set ^{CODESYS Forge talk (Post)}
A got a larger project but this very small example makes it clear. I have a button, and after it's clicked a lamp should flip on and stays on, and when the mouse-button is released it should stay on. When I try that in the PLC_PRG it works, but when I change it to a function block (seet attched demo proj) it isn't. I'm fairly new to PLC programming but are very experienced C# engineer, but this goes above my head...
Last updated: 2024-05-26

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