Post by otbeka on CAA File Handling: "Read only" error ^{CODESYS Forge talk (Post)}
Hi, On CODESYS V3.5.19.50 I am using the latest 3S File Access library (CAA File & CAA Types) to save and retrieve configuration data from the User Data section of an SD card, via file called config.txt. The application reads the file to memory once upon initialisation, and then the only other operation is overwriting the file with the updated configuration whenever the user changes the settings. An issue is ocurring, seemingly randomly, where the config.txt file, and all surrounding directories, cannot be written to by the unit, returning a READ_ONLY_CAA error upon file open. This sometimes does not clear even after power-cycling the PLC several times, yet checking the file permissions with ls -l shows normal read, write, and execute access. I am wondering if this is caused by the PLC itself or by an issue in my application. I have included my CAA File handler function block (SD_Card_Bin(FB).txt) and any associated types/calls below: TYPE ConfigData : STRUCT Config : ARRAY[0..256] OF STRING(64); NumberOfStrings : UDINT; END_STRUCT END_TYPE TYPE Buffer : STRUCT Data : ARRAY[0..SIZEOF(ConfigData)] OF BYTE; DataLength : UDINT; END_STRUCT END_TYPE A case within my MAIN PRG: mode.WriteConfigDataToFile: VisuElems.CURRENTVISU := 'Screen_Write'; IF xModeHasChanged THEN iErrorCount := 0; iRoute := 0; END_IF CASE iRoute OF 0: inBuffer := ConfigData_To_Buffer(GVL.UnitData); xConfigError := FALSE; xDataConfigured := FALSE; iRoute := 1; 1 : //Read Data from Card SD_Card_Bin.strFileName :=FileName; SD_Card_Bin.iFileOperation := 2; SD_Card_Bin(xExecute :=TRUE, WriteBuffer := inBuffer, xDone =>xDataConfigured, xError=>xConfigError, strErrorCodes=>strError); IF xDataConfigured THEN SD_Card_Bin(xExecute :=FALSE); IF xConfigError THEN iRoute := 32767; ELSE iRoute :=100; END_IF END_IF 100: // The end bCurMode := mode.DisplayProcessVariables; 32767: // Config error iErrorCount := iErrorCount + 1; IF iErrorCount > 2 THEN // Repeats 3 times, if no progress abandons and returns error bCurMode := mode.WriteError; ELSE iRoute := 0; // Try again END_IF END_CASE I'd like to rule out my application as the cause of this bug - help via comments or criticism would be greatly appreciated.
Last updated: 2025-03-19

Post by lacypaige on Engineering Dissertation Help & Assignment Assistance. ^{CODESYS Forge talk (Post)}
This thread is for discussing engineering dissertation help, including research methods, choosing a topic, writing, and data analysis. Whether you need advice on structuring your dissertation, understanding industry trends, or solving research challenges, this is the place to ask questions and share ideas. Feel free to exchange tips, discuss best practices, and get support with engineering assignments and dissertations.
Last updated: 2025-03-19

Post by kevinm on Attaching Trace variable to Frame Configuration Variable ^{CODESYS Forge talk (Post)}
Is it possible to show a variable from a Frame Configuration in a Trace on that Visualization? I want to pass the FB for an AXIS_REF_ETC_SoE_Standard to the visualization and display live axis data in the visualization. However, I cannot find a way to use a Frame Configuration variable in the Trace Configuration dialog.
Last updated: 2025-04-04

Post by timvh on update data/tim ^{CODESYS Forge talk (Post)}
Change the actual time of your PLC. How to do this sometimes depends on the PLC you use. Please contact the vendor of the PLC to get this information. Or see the following example for using CODESYS date and time functions: https://forge.codesys.com/prj/codesys-example/date-and-time/home/Home/
Last updated: 2025-08-26

Post by jy77812 on Visualization XY Charter Question ^{CODESYS Forge talk (Post)}
Hello. I'm using Visualization XY Chart, and when I mark a circle through XY position data, a blue line is displayed in the circle with a red circle. At this time, can't I set the blue line not to be seen in the circle? Currently, whenever XY position is drawn, the line follows.
Last updated: 2025-10-02

Post by davidbo on i2c How does CODESYS handle exception or error messages. ^{CODESYS Forge talk (Post)}
For Raspberry Pi I have made a python script which regularly read a bulk of data over the ic2 from a device. Sometimes I get an Exception an IOError. I assume similar things can happen in CODESYS. So how does CODESYS handle that? Can I get any info about such an event?
Last updated: 2024-02-07

Post by reinier-geers on SysFileOpen does not work after update to V3.5 SP19 Patch 5 ^{CODESYS Forge talk (Post)}
At 19.1 the hFile_test should be RTS_IEC_HANDLE and always open-write - close in one cycle udi_handle: RTS_IEC_HANDLE; //handle-number. Is created by SysFileOpen udi_handle:=SysFileOpen(sFileName,Sysfile.AM_WRITE_PLUS, ADR(udi_ErrorCode)); udi_RetValWrite:=SysFileWrite(udi_handle, pRemBuffer, szRemBufSize, ADR(udi_ErrorCode)); //closing file IF udi_RetValWrite < szRemBufSize THEN ui_Error:=cWriteError; END_IF//error writing data udi_ErrorCode_Close:=SysFileClose(udi_handle);
Last updated: 2024-02-19

Post by i-campbell on Not able to see input data coming from eip adapter on codesys ^{CODESYS Forge talk (Post)}
Hello, I think you can try to change the Connection from Multicast to Point to Point. Please also make sure your windows firewall is allowing the correct UDP ports inbound for ethernet IP. You might also need to increase the RPI, so it times out slower.
Last updated: 2024-03-07

Post by rjonker on codesys mqtt publish serialization ^{CODESYS Forge talk (Post)}
pbPayload is a pointer, which it expects to point at a STRING. If you point it at an address holding a different data type, it will just assume those bytes are part of a string and likely trundle along memory until it finds a null byte (0x00) that would normally signify the end of a string PublishMessage := BOOL_TO_STRING(boolVariable);
Last updated: 2024-06-05

Post by mos89p on how to use UseDataExpanding() in datasource ^{CODESYS Forge talk (Post)}
Hi I need to update by software some structures in my datasource, i found this example: https://content.helpme-codesys.com/en/CODESYS%20Communication/_cds_update_data_interface.html it seems that because i use complex variable structure i need to use UseDataExpanding() instead of use data, the question is how to get an instance of IDatasourcesMgr3 i have the global variable g_Datasources is instantiated automatically
Last updated: 2024-06-18

Post by koppit on SysComRead Timeout Parameter ^{CODESYS Forge talk (Post)}
Im using SysCom ver. 3.5.17.0 and seem to have the same issue on a Raspberry Pi. It's not waiting for the requested number of bytes, no matter if "ulTimeout := SYS_INFINITE" or any other value. The only solution I have found is to stall the program to allow the serial port to recieve the data.
Last updated: 2024-06-26

Post by vtec35 on search runtime 4.9.0.0 for pi 3 ^{CODESYS Forge talk (Post)}
Hello everyone, following corrupted data on the SD card of our Pi3B+ provided with a machine, we reinstalled a CODESYS image for Raspberry Pi, but we cannot find the 4.9.0.0 runtime that is compatible with the project. Currently, the machine is on 4.1.0.0, and we tried a more recent version 4.13.0.0, but there are error messages. Thanks in advance.
Last updated: 2025-10-24

Post by kporter on SoftMotion, accessing PDO input data via object ref/pointer ^{CODESYS Forge talk (Post)}
Now that SP21 is out, what's the answer? I want to get a pointer to the TxPDO and RxPDO structs. I can generate a STRUCT declaration from the ESI file with a bit of Python. I just need to get the pointer from the ETC_Slave.
Last updated: 2025-10-29

Post by aniket-b on Scara3 kinematic robot error ^{CODESYS Forge talk (Post)}
Here I have attached the task monitor data. What is very weird is that I am using MC__MoveDirectAbsolute FB, when I choose Vel/ACC/Jerk Factor to 1.0 it run fine. It ran 10 hours without the issue. But I get the error randomly when I use factor as 0.5
Last updated: 2025-12-29

Post by kaotic2499 on Upgraded Raspberry 2b to Raspberry 5, Trends Broken? ^{CODESYS Forge talk (Post)}
There is currently a bug with the Raspberry Pi 64 SL where it is unable to Trend Global Retain or PersistantVars. The work around is to use standard Global Variables for Trend Data. This will be patched by Codesys in the near future reference "VIS-6170"
Last updated: 2025-11-13

Post by yr00 on OPC UA datasource low read frequency ^{CODESYS Forge talk (Post)}
Hello everyone, I am trying to test the OPC UA client feature in Codesys. My setup is the following; I have a Codesys simulation/ visualization running on Control Win V3. My OPC UA server is hosted on a Siemens 1518 PLC using PLCSim Advanced. The setup is completely virtual so there are no really PLCs. Everything is on my laptop. Writing data from the Codesys simualtion to the server is very quick. I have a PLC program running on another 1500 PLC which reads data from simulation via the server, and changes in the simulation (e.g. button pressed) appear within hundreds of miliseconds if not tens of miliseconds in my PLC program. However, when it comes to reading data from the OPC UA Server by Codesys, it taks around 1-2s. I connected a UAExpert client and it gets update very quickly so I am fairly sure the problem is with Codesys. I have tried changing the update rate in datasource -> General and Diagnosis, but it doesn't seem to have an effect. Do you guys have any suggestion on what I can do?
Last updated: 2023-08-29

Post by egret on Issue with J1939, PGN 65267 (Vehicle Position) ^{CODESYS Forge talk (Post)}
I have a J1939 network (ISOBUS) connected to my PLC. I can receive various PGNs such as 65256 (Vehicle Direction/Speed) and 65254 (Time/Date). However, I cannot receive 65267 (Vehicle Position). PGN 65267 (VP) contains SPN 584 (Latitude) and SPN 585 (Longitude). On the network both SPNs return a value of -210 (meaning the CAN message payload is zero in both cases). The conversion settings are the default values and appear to be correct (see attached screenshot). Using a CAN analyser I can see that PGN 65267 (Vehicle Position) is being transmitted over the network with valid (non-zero) data that matches the latitude and longitude coordinates I would expect. I've created a program to read the raw J1939 data and this also returns valid data. It seems that the Codesys J1939 database has a problem with reading PGN 65267 messages. Can anybody else confirm this? I'm using Codesys Version 3.5 SP16 Patch 5.
Last updated: 2023-09-13

Post by andrej on Write to File on soft PLC winV3x64 ^{CODESYS Forge talk (Post)}
Hello all, I would like to store some data in text file. I use the soft PLC Win V3x64, on Windows 10. I use the SysFile Library 3.5.17.0. If I store the file directly in the in the directory of the PLC i.e. in '/CODESYSControlWinV3x64/E1FA7ABE/PlcLogic/LogAU.txt' the file is correctly filled with the data. However, If I use an absolute path to a different directory no data is stored in the respective file. Despite the fact that the respective file exists and the Filehandler is correctly opened (see in picture _fdSysFHandle <> -1). // sFileName : STRING := 'LogAU.txt'; // STORES FILE IN ../CODESYSControlWinV3x64/../PlcLogic/LogAU.txt' sFileName : STRING := 'C/Temp/LogAU.txt'// DOES NOT WORK --------------------- // FILE DESCRIPTOR _fdSysFHandle := SysFile.SysFileOpen( szFile:= sFileName,am:= SysFile.AM_APPEND,pResult := ADR(_Result)); Does some have an idea where the problem is, resp. how I can get store a file in an arbitrary directory. Thanks a lot and kind regards Andreas
Last updated: 2023-10-24

Post by razebones on sdo read write codesys 3.5 ^{CODESYS Forge talk (Post)}
ENG For some reason, I can't bind a variable to the data parameter. Also, why does only the sdo_read4 function work for me? I also can't write through sdo_write4. I can only view the received values via sdo_read4. Please help me with this task. Moreover, I tried to write the values through sdo write 4 and for a while the data stopped being written and I overwritten it manually and sdo read4 started working again and at the same time they do not want to work in the main task. RU Я не могу почему то привязать переменную к параметру data. Так же у меня почему работает только функция sdo_read4 так же не могу записать через sdo_write4. Могу только просматривать полученные значения через sdo_read4. Помогите пожалуйста с этой задачей. Причём я попытался записать значения через sdo write 4 и у меня на какое то время перестали записываться данные и перезаписал вручную и sdo read4 начал работать снова и одновременно они не хотят работать в main task.
Last updated: 2025-04-01

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 shrikantp007 on help to get codesys understand ^{CODESYS Forge talk (Post)}
Hello , I need some help on how to start with , 1) how to get test license to test codesys , 2) how to take a configuration backup or running process back and post file on fourm so people can understand and deploy same file and get idea what is missing or configure wrong 3) where i can get pdf for codesys admin or programmer 4) what is hardware recommand ,i am running on windows guest on kvm server .is it ok ? 5) i am trying to get ardunio porject working ,using ardunio board as a modbus slave but its not working some how https://forge.codesys.com/forge/talk/Engineering/thread/bf832569b8/ Thanks in advance . shrikant pune -india
Last updated: 2024-07-22

Post by yannickasselin on codesys VLAN tagging ^{CODESYS Forge talk (Post)}
I ordered a cheap managed switch and tested it as soon as I received the switch. It works great! I even went a bit further. As you can see in the screenshot, I created 2 Codesys containers. Each one having 2 fieldbuses. The first one has EtherCAT and EtherNet/IP and the second one has EtherCAT and Modbus/TCP. All going through the same ethernet port from the PC to the switch. The switch splits it up into 4 different networks. The hardest part was to figure out how to configure the switch. @eschwellinger, thank you very much.
Last updated: 2024-09-17

Post by timvh on Modbus TCP & RTU with Control for Linux SL ^{CODESYS Forge talk (Post)}
It seems you have 2 network interfaces. Did you try eth1? Did you already configure the IP address for this interface in Linux? If yes, then maybe undo this. - or only set eth0 in the Nic configuration without anything else (so no IP address, because this is already set in Linux). For more information about the Nic settings, see (probably already read it?): https://content.helpme-codesys.com/en/CODESYS%20Control/_rtsl_obj_deploy_control_sl_configuration.html PS, if you only want to run CODESYS Control SL, you don't necessarily need the Virtual PLC variant. You could also install and run the CODESYS Control SL Runtime in the Host operating system. This way you should also be able to access the serial port and directly access all ethernet ports. Maybe this is easier?
Last updated: 2024-10-23

Post by ben1 on How to write multiple coils (Modbus FC15) ^{CODESYS Forge talk (Post)}
If I am understanding what you are saying, then yes that would be your problem. I would create an array of bools on the client side for the transfer and try that. Or if client can't be changed then use words on server and unpack. But I am not sure if you or I are mis interpreting but it sounds a bit jumbled. I don't know what you have control of, but, if you are turning on BITS in the server, you should write to BITS in the client with a Function 15. If you are writing to WORDS in the server, you should write to WORDS in the client with a Function 16.
Last updated: 2024-11-17

Post by rafa on MODBUS TCP SERVER DONT AUTO-STARTUP ^{CODESYS Forge talk (Post)}
Dear all, I have a project where I have two ModbusTCP communication drivers in the application. It's working normally until a power outage or the installation panel is restarted. As soon as the PLC CPU is restarted, the Ethernet port is OK, but the TCP Server displays an "UNDEFINED" error. I can't reset the error using the diagnostic confirmation or the "mbserver.xConfirmError" bit. I noticed that the error only appears in the "mbserver.byModbusError" memory and the description is "UNDEFINED." The "mbserver.xError" memory doesn't flag an error. When using the warm restart function and then START CPU, the devices return to normal operation. The following demonstration images; The main question is: How can I make devices boot automatically?
Last updated: 2025-07-15

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