Post by gilbert-mh on CAA net base TCP client cause PLC to crash - Kernel message : N0HZ_local_softirq_pending 80 ^{CODESYS Forge talk (Post)}
Hello all, I have been trying to implement a TCP client on a Festo PLC (CPX-E-CEC-M1) and it looks like it works well except that after some time (greatly varies between a few hours to more than 100h) my PLC crash. When I look into the log file the only thing I see is that before the crash happens a few kernel warnings : N0HZ_local_softirq_pending 80 and then the crash. I've looked into this warning and from what I could find on the net it seems that this is warning is triggered when the ethernet link is down. I've tried to correct this bug for quite some time and what I know is that : - The crash is caused by my TCP client, when I remove it from my code I see no crash - The crash happens more quickly the more the TCP client is used. - The time before the crash is not directly proportional to the number of communications or their size. But it looks like it is just more likely to happen if the client connect to the server at a higher frequency. - The precedent observation makes it seem unlikely that the crash is caused by some memory overflow because then the crash speed would be more proportional to the amount of data exchanged. SO from these observations, I believe that the crash could be caused by the PLC trying to connect to a server while there is some kind of issue with the ethernet link resulting in the PLC getting stuck in some indefinite state and making it crash. This still seems a bit unlikely to me because if the ethernet is down it simply shouldn't be able to contact the server and the communication would just fail which doesn't cause my PLC to crash. Has anyone encountered the same kind of problem (with the same kernel message) ? I am pretty sure the warning is not the direct cause of the crash but just an indicator that something is wrong with my PLC. Thanks in advance
Last updated: 2024-01-12

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

How to use more 4 instances of CANopen/Profibus/Modbus with The application-based license CODESYS Control ^{CODESYS Forge talk (Thread)}
How to use more 4 instances of CANopen/Profibus/Modbus with The application-based license CODESYS Control
Last updated: 2023-11-02

Post by gorditron on Modbus Slave RTU in der Applikation abschalten ^{CODESYS Forge talk (Post)}
Hallo, gibt es eine Möglichkeit die Modbus Slaves (ModbusSlaveComPort) innerhalb der Applikation über ein Variable zu aktivieren oder zu deaktivieren? Bilder als Datei Danke!
Last updated: 2023-11-09

Post by gatto on Application-based license Modbus Channels ^{CODESYS Forge talk (Post)}
Hi Sandro, did you find any solution? I'm in version 3.5.20.40 and i have only one modbus channel. I don't want the problem to happen to me if I do an update one day.
Last updated: 2025-09-01

Post by tobifenny on Modbus TLS Kommunikation ^{CODESYS Forge talk (Post)}
Hier ist das handbuch: https://www.kostal-solar-electric.com/fileadmin/downloadcenter/kse/BA_KOSTAL_Interface_KSEM_DE.pdf Im Kapitel 1.3.2 ist das mit dem TLS beschrieben und in Kapitel 3.6.2 sind die Modbus-Register beschrieben.
Last updated: 2 hours ago

Post by davidbo on Is OPC communication possible with server certificate but no client certificate ^{CODESYS Forge talk (Post)}
I was just wondering is the following option possible and what the settings should be. Is OPC communication possible with only and mandatory server certificate but no client certificate?
Last updated: 2023-10-06

Post by kjubidoo on OPCUA Ctrl-Node fehlt ^{CODESYS Forge talk (Post)}
Perfekt, das war es. Node ist zu sehen. Es hat mich schon etwas gewundert, dass die Zertifikatverwaltung zwischen Codesys und WBM auseinander lief. D.h. der OPCUA Server, den man im WBM konfigurieren kann, ist (in diesem Fall mit einem 750-8202) der WAGO OPCUA-Server?
Last updated: 2023-12-05

OPC-UA Server, Symbol Set: Raise an error: Object reference not set to an instance of an object. ^{CODESYS Forge talk (Thread)}
OPC-UA Server, Symbol Set: Raise an error: Object reference not set to an instance of an object.
Last updated: 2024-08-08

Post by elayaraj on Codesys Soft PLC OPC UA server ^{CODESYS Forge talk (Post)}
Hi guys, I also facing the same issue on my project, trying to connect server (Codesys) to UA Expert but the connection keep failed(attached). Im running out of idea right now..please help!
Last updated: 2024-08-22

Post by damian177 on OPC UA Client ^{CODESYS Forge talk (Post)}
The OPC UA Client Example with webvisu is working. Now I would like to use Datasource to connect to OPC UA Server but some is wrong because nothing to do when I try list tags from server - please find in attachement
Last updated: 2024-09-03

Post by damian177 on Problem with downloading OPC UA tags by Data Source Manager ^{CODESYS Forge talk (Post)}
In my OPC UA Server is about 12 thousands tags. Can by possible that downloading tags from OPC UA Server lasts a long time , and when expires about 2 hours (demo license time) that downloading freezes ?
Last updated: 2024-09-04

Post by thn-power on Opaque NodeId in the OPC UA server ^{CODESYS Forge talk (Post)}
I'm wondering the same. Using the old symbol configurator opc ua server gave the node id using a string. Must be a way to specify this at build time?
Last updated: 2024-12-16

Post by winki on OPCUA Server With COntrol For Linux Arm64 ^{CODESYS Forge talk (Post)}
Hello, I am wondering if it is possible to have OPCua Server with Control for linux ARM64. Indeed I am not able to add symbol configuration.
Last updated: 2025-01-13

Post by romrot on Trying to connect Codesys OPC server to Ignition ^{CODESYS Forge talk (Post)}
Does the OPC UA server have a generic username and password? It doesn't seem to be the same as the device username and password.
Last updated: 2025-01-22

Post by romrot on Trying to connect Codesys OPC server to Ignition ^{CODESYS Forge talk (Post)}
Does the OPC UA server have a generic username and password? It doesn't seem to be the same as the device username and password.
Last updated: 2025-01-22

Post by atef on CODESYS V3.5 SP19.7 on windows server Installing error ^{CODESYS Forge talk (Post)}
Hi, while installing CODESYS V3.5 SP19.7 on windows server 2022 standard 21H2 I got error 2732 directory manager not initialized Has anyone faced this problem before or found a solution? Any guidance would be greatly appreciated. Thanks in advance!
Last updated: 2025-08-04

Post by atef on CODESYS V3.5 SP19.7 on windows server Installing error ^{CODESYS Forge talk (Post)}
Hi, while installing CODESYS V3.5 SP19.7 on windows server 2022 standard 21H2 I got error 2732 directory manager not initialized Has anyone faced this problem before or found a solution? Any guidance would be greatly appreciated. Thanks in advance!
Last updated: 2025-08-04

OPCUA-Client on raspberry pi can not communicate with OPCUA-Server on raspberry pi installed with CODESYS runtime ^{CODESYS Forge talk (Thread)}
OPCUA-Client on raspberry pi can not communicate with OPCUA-Server on raspberry pi installed with CODESYS runtime
Last updated: 2021-11-11

Post by flavinhofh on Beaglebone Black OPC-UA Server ^{CODESYS Forge talk (Post)}
ah ok, I will keep trying, I already removed all security from the Server side. I'm new on codesys and I don't know yet how to implement the certificates, but I will find out and also try. thanks for your reply.
Last updated: 2024-04-11

Post by dgdamt on Beaglebone Black OPC-UA Server ^{CODESYS Forge talk (Post)}
Hello, In my case all was ok on the BeagleBone side (OPC server) but wrong on the client side (was OK with UA Expert who manage properly its own certificates. I finnaly removed all security settings
Last updated: 2024-04-16

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 dawidr on Best practices for querying multiple MODBUS devices ^{CODESYS Forge talk (Post)}
Hi! What are the best practices for querying multiple Modbus devices? Single PRG or maybe multiple PRG (so basically multiple thread) per each Modbus device. In my current implementation I'm using single PRG and I'm utilizing FbMbMasterMultiQuerySerial and WagoAppPlcModbus.FbDigitalTwinMbSlaveDevice in eCockpit with PFC200. I've the timer with 2 seconds delay there and it was working fine for single device. But now I have three Modbus devices and for two of them I need to run 2/3 queries to get data from all registers. I noticed that the delays for getting the data from the Modbus devices is much bigger right now.
Last updated: 2024-07-31

Post by jp23 on Unable to Connect to Modbus RTU Device ^{CODESYS Forge talk (Post)}
Hi all, I am attempting to use the Control Win V3 soft PLC to control a WAGO 750-315 remote I/O system via modbus RTU communication. I am struggling to connect to the device. I have been following this tutorial: https://www.youtube.com/watch?v=YlRfkESaNds I have setup my devices as shown in the images below. I have verified that my com port settings are correct as I am able to connect/control using modbus simulator software with these settings. I have also connected to a modbus master simulator program as instructed in the video, but the orange triangles will not go away. Additionally, I have updated my settings to 485 using the PLC shell. I have also set "always update variables" to enabled (1). Serial port, PCI-Bus, and modbus serial device status all show as "Not Running."
Last updated: 2024-08-26

Post by jp23 on Unable to Connect to Modbus RTU Device ^{CODESYS Forge talk (Post)}
Hi all, I am attempting to use the Control Win V3 soft PLC to control a WAGO 750-315 remote I/O system via modbus RTU communication. I am struggling to connect to the device. I have been following this tutorial: https://www.youtube.com/watch?v=YlRfkESaNds I have setup my devices as shown in the images below. I have verified that my com port settings are correct as I am able to connect/control using modbus simulator software with these settings. I have also connected to a modbus master simulator program as instructed in the video, but the orange triangles will not go away. Additionally, I have updated my settings to 485 using the PLC shell. I have also set "always update variables" to enabled (1). Serial port, PCI-Bus, and modbus serial device status all show as "Not Running."
Last updated: 2024-08-26

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