Post by egr99 on Modbus TCP Server connection is ESTABLISHED but all holding registers are value 0?
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You're absolutely right. Sorry for that. In the meantime I wrote a Function block to handle the reads and writes to the different attached RTU-devices. It processes the parameter like (str_Modbus:=(usiSlave:=1, uiFC:=5, uiLEN:=1, uiOFFSET:=0, uiInterval:=500)) and the corresponding output, waits for the response and processes next request in a 5-state procedure. It's working for 2 gateways (stable without errors, although error recovery is included). But nevertheless it should be possible with the Channel definitions of Codesys. Much easier to maintain :)
Last updated: 2026-04-08
Post by alexgooi on Network variable stops sending
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Hi Reinier, What usually works for me is settings it up in the following way: In the sender block make sure that the list identifier is unique for the whole installation (this is only relevant when you have multiple senders in 1 network). When you are linking the NVL to a file make sure that the path to this file doesn't change. In my experience the NVL stops working when you change the working directory and afterwards open the NVL in de Codesys IDE. If this doesn’t apply to you application, you could also try to change the port number, maybe there is an other process making use of port 1202. Kind regards Alex
Last updated: 2026-04-22
Post by timvh on library inside library
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1) it should be possible to access the type SysTime in the project as A_Lib.SysTime. 2) you could add the SysTimeCore library to the library manager of your library (POU Pool). This might seem as a double library, but because of the placeholder resolution only one will be used. Then, in your library manager of your library, select the SysTimeCore library, right-click, select "Properties" and enable the option "Publish all IEC symbols ...." For more information about library development, you could follow our advanced training course in Ridderkerk. The next is scheduled for 24 and 25 June 2026 https://www.extendsmartcoding.nl/codesys-training/
Last updated: 2026-04-25
Post by brouwyka on JSONByteArrayWriter problem?
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Hey there! I am currently running into the exact same issue. The JsonData object has all inexes & parent indexes in the way I expect, everything is correctly "linked". It purely seems that the writer is incorrectly parsing said JsonData, not based on parent & child index, but on something else that breaks it and puts things at the root, instead of the specified parent index. Did you ever manage to find a solution, or another way of achieving your JSON composing? I'm currently working on Codesys V3.5 SP19 Patch 7 with IIOT Libraries SL 1.13.0.0, specifically JSON Utilities SL 1.13.0.0 (to send requests to APIs with JSON bodies using Web Client SL 1.13.0.0).
Last updated: 2026-06-08
Post by brouwyka on JSON Utilities - JSON file written with invalid structure
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Hey there! I am currently running into the exact same issue (and have also posted to a similar post here: https://forge.codesys.com/forge/talk/Engineering/thread/c45929e2f1/#e27f). The JsonData object has all inexes & parent indexes in the way I expect, everything is correctly "linked". It purely seems that the writer is incorrectly parsing said JsonData, not based on parent & child index, but on something else that breaks it and puts things at the root, instead of the specified parent index. Did you ever manage to find a solution, or another way of achieving your JSON composing? I'm currently working on Codesys V3.5 SP19 Patch 7 with IIOT Libraries SL 1.13.0.0, specifically JSON Utilities SL 1.13.0.0 (to send requests to APIs with JSON bodies using Web Client SL 1.13.0.0).
Last updated: 2026-06-08
Post by cd-tt on cannot connect ot linux runtime: device does not answer the scanrequest
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I have the following setup: Proxmox PC with a debian 13 VM running CODESYS Control Linux SL and Edge Gateway. Installation method was through the Deploy Control SL and went rather smoothly. In my Device Tab I find the gateway and when scanning my network I also find my runtime. I want to connect and get promted that I should add a user. After setting up the user I get an error saying, that the device is not responding my scanrequest. Deploy Control SL Operation saying everythings up and running. I can confirm that from the terminal on the VM with "systemctl status codesyscontrol" and "systemctl status codesysgateway". I am running out of ideas how to fix that issue. Can anybody help? Screenshots attached.
Last updated: 2026-06-11
Post by steven-schalm on Frustration-Fueled Feedback on Project File Management and Git Integration
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Yes, it's very tedious, especially since Codesys 4 is a custom web development... At Rex Automatisierungstechnik GmbH, we've invested a lot of time in the Python interface to enable something like CI/CD, but also to export the code and re-import it after making clean modifications. Also, the fact that a class/function block is just a single file containing all the methods, props, etc. Yes, and right now I’m building my own VS Code extension with a clean LSP (Language Server Protocol) for ST, as well as an st-validator, st-formatter, st-linter, codesysPackage.json, and codesys_modules folder... Best regards, Steven Schalm / Sharok6130
Last updated: 2026-06-11
Post by williamcorlin on The future and proper use of CAA.BOLT, CAA.SEMA,..
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I've been moving in the same direction. For new libraries, I'm trying to minimize dependencies on APIs that look like they're being phased out unless the documentation explicitly recommends them. For synchronization primitives like CAA.BOLT and CAA.SEMA, I'd love to see an official replacement or abstraction layer that's guaranteed to remain stable across runtimes. That would make library development much cleaner than relying on platform-specific SysLib* implementations or conditional compilation everywhere. Until there's clearer guidance, my approach has been to isolate the locking mechanism behind a small wrapper interface. If CODESYS changes the recommended API in the future, only that wrapper needs to be updated instead of every library that uses it. It isn't perfect, but it's made maintenance much easier. https://forge.codesys.com/forge/talk/Engineering/thread/e6c20a740e/ https://zapgames.io/
Last updated: 2026-07-14
Post by bbm1995 on Security Screen - Custom Certificates for OPC UA Server?
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Hi everyone, is it possible to use selfsigned/created certificates (eg. with X - Certificate and Key Management) as a OPC UA Server certificate in the Security Screen? As far as I know I can only upload client certificates to the PLC and move it to "Trusted", "Untrusted" and "Quarantined". Same question is on sps-forum.de
Last updated: 2023-08-23
Post by vformanek on No source code available for profinet library
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I have tried downgrading and it seems fine now. I am now on version 4.3.0.0 for the library. Mainly the PN controller caused the issue for me. Funny weird is that even the PN controller versions 4.3.1.0 and 4.3.0.0 cause the error. Version 4.2.0.0 works fine.
Last updated: 2023-08-23
Post by fless on No source code available for profinet library
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looks like you are running in a bug in the newest version 4.4.0 of the profinet library or the new library triggers a bug in your code. did you update your profinet device too? you could try to downgrade to an older version of the library. via library manager - placeholders, double click Profinet 4.4.0 in the library column and choose an older version.
Last updated: 2023-08-23
Post by transmin01 on EL6751 Canopen_Manager issue
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Hi, I have a Beckhoff EL6751 EtherCAT / CANopen gateway which fails on the Canbus when the CANopen_Manager is added. Currently no devices are connected to the EL6751. If I add a device, I get the same issue. If I add a device and connect the bus, I get the same issue. Is there something I am doing wrong? Regards Trevor
Last updated: 2023-09-12
Post by spareparts on SPI Master not running/MCP3008 Missing driver.
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I believe I have installed the correct device descriptions and library, in an attempt to use the MCP3008 in conjunction with RPI; when project runs the MCP3008 is unable to find the correct driver. Is there anything I'm missing? Very new to this so any help is apprecated!
Last updated: 2023-09-12
Post by kdasystems on WebVisu on mobile devices
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Hello I have a problem with web visu. When I open it to normal screen it is with good quality, but when I use it on mobile phone or tab then it is really bad quality, almost not possible to read the information. Can somebody help me what are the exact settings in the visu manager for this
Last updated: 2023-09-13
Post by transmin01 on EtherCat Master cannot open network adaptor on Win10x64 target
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Hi, If I utilise an EtherCat master with a Beckhoff EK1100 coupler on a Win10x64 target I get a "Network Adaptor could not be opened" error. I have tried this on both a VM and a physical PC. Has anyone experienced this issue? Regards Trevor
Last updated: 2023-09-14
Post by derpaul on Official MQTT-Client: MAX_RECEIVE_BUFFER_SIZE_EXCEEDED
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Hello, my PFC200 has run for a few month now without problems. But now it freezed 2 times a day. LEDs were green but the PLC was not reachable. After power off -> on. I found that the MQTT had an error: MAX_RECEIVE_BUFFER_SIZE_EXCEEDED. And MQTT hadn't reconnect since then. I tried a cold and a warm reset but nothing helped. How can I solve this? Regards, Paul
Last updated: 2023-09-21
Post by lucaver89 on Raspberry pi 3 and runtime 4.9.0.0
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Good morning, I'm using a raspberry pi3 as plc with the runtime 4.9.0.0. My program has many of retrain variables but when an update is performed the retrain variables comes back to default values. Is the a way to backups the retrain variables n a csv file? Is still the way to restore them from the csv? Thank you for helping Luca
Last updated: 2023-09-23
Post by transmin01 on SafetyApp - "Invalid ERR Ack input"
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Hi, I am trying to get a basic safety application to download but I keep getting an "Invalid ERR Ack input" and "The Standard Inputs Size of zero is not allowed". I am simply using 2 safety inputs through an "AND" block to 2 safety outputs. Any help would be appreciated. Regards Trevor.
Last updated: 2023-09-27
Post by transmin01 on SafetyApp - "Invalid ERR Ack input"
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Hi, I am trying to get a basic safety application to download but I keep getting an "Invalid ERR Ack input" and "The Standard Inputs Size of zero is not allowed". I am simply using 2 safety inputs through an "AND" block to 2 safety outputs. Any help would be appreciated. Regards Trevor.
Last updated: 2023-09-27
Post by transmin01 on SafetyApp - Exchange 8 bits from EtherCAT Safety Module to PLC mapping issue
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Hi, I am using an "Exchange 8 bits from EtherCAT Safety Module to PLC" module which allows me to create tags in the safety environment, but how does this map to the standard PLC program? There is no entry in the IoConfig_Globals variables list. Regards Trevor
Last updated: 2023-09-27
Post by tk096 on Motion FB Error
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Hi, Softmotion Robotics does not support tracking in/out to dynamic coordinate systems with relative movements. Is MC_MoveLinearAbsolute an option? See SMC_RELATIVE_MOVEMENT_TRACKING_CS in https://content.helpme-codesys.com/en/libs/SM3_Error/Current/SM3_Error/SMC_ERROR.html Concerning the other error: Do you use any motion function blocks of SM3_Basic to move a single axis of the robot in your application?
Last updated: 2023-10-20
Post by laruso on Runtime device Enable/Disable procedure
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I implemented the parts from the CAA Device Diagnosis Example.project and could use it for switching on and off, the CAN devices that were located under the CANbus and CANopen_Manager. But i can't do the same with I2C_master_test_version or devices below this one. In the example project there is only the EtherCAT Master, CANbus and CANopen_Manager, and Ethernet with devices below.
Last updated: 2023-10-27
Post by andrax on Mux I2C
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Hi, sorry I was not there for a long time. The TCA9548 needs terminating resistors, do you have them in? That's why I went to QWIIC, the muxboard already has them built in. If it still does not work, try it first without the muxboard. PS: Note the channel assignment. Muxboard 0 = I2C_Master 1,0,0,0,0,0,0,0 Muxboard 1 = I2C_Master 2,0,0,0,0,0,0,0 etc.
Last updated: 2023-10-29
Post by bernd on Version 3.5.19.40 probleme bei FUN mit _to_ im Name
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@PaRo erst mal vielen Dank für die Antwort. Wundert mich das so ein schwerer Bug nicht sofort gefixt wird. Wenn es keine offene Lib wäre, wäre keine Workaround möglich. Auch bei einem bestehende umfangreichem Programm nicht wirklich praktikabel. Gibt es irgendwo eine Liste mit bekannten Bugs? Gefunden habe ich nichts. Ich muss wohl wieder auf die alte Version zurück.
Last updated: 2023-11-14
Post by ewi04 on Recipe Manager - RecipeManCommands, load & write wrong values, Bug?
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The individual structures were declared in a separate global variable list on a trial basis. But even this did not change the behavior. A total of 1667 variables are processed in a recipe. A reduction (e.g. saving only the first three drive parameter sets) also brought no change.
Last updated: 2023-11-15
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