Post by mil581 on Modbus TCP Server connection is ESTABLISHED but all holding registers are value 0? ^{CODESYS Forge talk (Post)}
Hello everyone! I'm facing a weird issue with CODESYS Control Win V3 x64 on a fresh Windows install. The situation is as follows: CODESYS Modbus TCP Server (Slave) is running and I can see live values in the mapping display of Modbus settings: GVL (e.g., 32, 42, 50). Port 502 is LISTENING according to netstat. When connecting via Modbus Poll or Node-RED, the connection status changes to ESTABLISHED and everything reports as fine. The Problem: Despite the successful connection, all holding registers return 0 no matter what. It's like the OS accepts the TCP handshake, the request counter goes up but the data payload never reaches Modbus Client (in this case Node-RED or Modbus Poll). Quick Stats: Firewall: Completely OFF. Unit ID: Verified & Matching. IP: Tried 127.0.0.1 and 192.168.0.1. Interface: Correctly bound in Ethernet Device settings. I already tried absolutely everything from changing IP address, subnet, port, deleting the project and starting new one and even nuking my old Windows install. Since I am near completion of my bachelor thesis only thing left for me to do is connect SoftPLC to NodeRED via Modbus but this issue is driving me crazy for weeks. I do not know what to do anymore.
Last updated: 2025-12-25

Post by fredashbolt on Dynamically Update JSON Payload ^{CODESYS Forge talk (Post)}
I am trying to generate a JSON payload populated with a value that updates for use with a telemetry system, the payload is to be published by MQTT. I have established the MQTT client and can publish a working JSON payload but I can't get the payload to update as the value (iValue) changes. I am using a timer to trigger the .SetValue function periodically, but the JSON will only give the value as it is when it is first initialized using xFirst IF statement. Any suggestions? Thanks VAR pJsonData : POINTER TO JSON.JSONData := factory.Create(); fb_JBuilder : JSON.JSONBuilder; diRootIndex, diObject1Index : DINT; iValue : INT := 10 ; jsonArrayWriter : JSON.JSONByteArrayWriter; wsJsonData : WSTRING(1000); xFirst : BOOL := TRUE; utf8JsonData : STRING(2000); diTempVal : DINT ; PublishTimer : TON ; END_VAR IF xFirst = TRUE THEN fb_JBuilder ( pJsonData := pJsonData , diRootObj => diRootIndex ) ; diObject1Index := fb_Jbuilder.SetKeyWithObject ( "Device" , diParentIndex := diRootIndex ) ; diTempVal := fb_Jbuilder.SetKeyWithValue ( "Temp" , iValue , diParentIndex := diObject1Index ) ; xFirst := FALSE ; END_IF PublishTimer ( IN := PublishTimer.Q = 0 , PT := T#5S ) ; IF PublishTimer.Q THEN fb_JBuilder.SetValue ( iValue , diTempVal ) ; END_IF jsonArrayWriter( xExecute := PublishTimer.Q , pwData := ADR(wsJsonData), udiSize := SIZEOF(wsJsonData), jsonData := pJsonData^, xAsyncMode := FALSE ) ; JSON.Stu.ConvertUTF16toUTF8( ADR ( wsJsonData ) , ADR ( utf8JsonData ) , SIZEOF ( utf8JsonData ) , bStrictConversion := TRUE ) ;
Last updated: 2026-03-10

Post by mrkm-dic on UC20-M4000 Redundancy – Application is not automatically synchronized and redundancy breaks after online change ^{CODESYS Forge talk (Post)}
Hello, I am currently testing redundancy using two UC20-M4000 controllers with CODESYS Control SL. The basic redundancy functionality (Active/Passive switching and failover) works, but I am experiencing problems when updating the application. Environment Controller: Weidmüller UC20-M4000 OS: u-OS Runtime: CODESYS Control SL 4.12.1.0-1 Redundancy link: dedicated Ethernet connection between the two controllers Time synchronization: NTP configured, time difference between controllers is about 1–2 seconds Current behavior Application synchronization When I download a modified application to PLC1 (Active controller), the application is not automatically copied to PLC2 (Passive controller). However, when I perform a path swap, the application download to PLC2 starts automatically. My expectation was that the Passive controller would automatically receive the updated application after downloading to the Active controller. Online change When performing an online change, redundancy is lost and the controllers switch to Standalone mode. Typical log messages include: RedundancySynchronize called Redundancy failover itself works correctly. The application boot project exists on both controllers (Application.app and Application.crc). Network interfaces are up and correctly configured. Question Is this behavior expected when updating the application in a redundant UC20-M4000 setup? Should the Passive PLC automatically receive the updated application, or is manual synchronization required? Any advice or recommended configuration for stable redundancy during online change and application download would be greatly appreciated. Thank you.
Last updated: 2026-03-16

Post by kiranbsiddaiah on CodeSys OPC UA client Unable to Connect To OPC UA sever through Username and password ^{CODESYS Forge talk (Post)}
Hi, I'm using codesys v3.5 sp21 software. I have downloaded the sample opc ua client project from https://content.helpme-codesys.com/en/CODESYS%20Examples/_ex_uacapi_example.html and i tested connecting to "prosys opc ua simulation server". Through Anonymous connection it is connecting to server and can read data. Later tried to connect using username and password. First got a SECURITY_CHECKS_FAILED error, trusted the client certificate in the server and this issue resolved. Next got an INVALID_CERTIFICATE error, trusted the server certificate in the client and this issue resolved. After these two error it is not establishing the connection and not giving any error messages. UAAsyncProp: UA.AsyncProperty := (tnTaskName:='UAClientTask', usiTaskPrio:=20, udiTaskInterval:=10000); UAPolicy: UA.SecurityPolicy := (sPolicy:=UA.OpcUa_SecurityPolicy.OpcUa_SecurityPolicy_Aes128Sha256RsaOaep, eSecurity:=UA.SECURITY_MODE.SIGN_AND_ENCRYPT); //UAPolicy: UA.SecurityPolicy := (sPolicy:=UA.OpcUa_SecurityPolicy.OpcUa_SecurityPolicy_None, eSecurity:=UA.SECURITY_MODE.NONE); UAAuth: UA.UserNameAuth := (sUserName:=UAVars.sUser, sPassword:=UAVars.sPass); UAClient: UA.Client := ( itfAsyncProperty:= UAAsyncProp, //sClientName:= 'MyOPC UA client name', //default: ‘CODESYS OPC UA Client’ sURL:= UAVars.sURL, sSession:= UAVars.sSession, itfPolicy:= UAPolicy, itfAuth:=UAAuth, udiTimeout:= 100000 //,itfNamespaceArray:= UAVars.itfNamespaceArray //optional use ); ----------------------------------------------------------------------------------------------------------------------- Please let me know if any additional information required. Thank you...
Last updated: 2026-05-07

Post by alimans on Hex string ^{CODESYS Forge talk (Post)}
Hi kdkwhite, for Word you still can use suggested code by using a union structure and crack down your Word to two byte as bellow: TYPE CrackWordToByte : UNION InWord : WORD; OutBytes : ARRAY [0..1] OF BYTE; END_UNION END_TYPE then define your variable as this type: udInput : CrackWordToByte; now assign your Word variable input to InWord and send OutBytes[x] to the mentioned method: udInput.InWord := WordVariableInput; Input := udInput.OutBytes[x]; Regarding your question about the code: actually 48 is ascii code of "0" and while 65 is the ascii code of "A" so in above code 55 + 10 would be 65.
Last updated: 2023-09-20

Post by damian177 on Codesys V3.5 + Pixtend v1.3 + RaspberryPi ^{CODESYS Forge talk (Post)}
Hi, I use Pixtend v1.3 with my RaspberryPi with Codesys V3.5 SP15 Patch1. Actually in my project I used two packages: - CODESYS Contro for Raspberry PI 3.5.15.10 - PiXtend for CODESYS 1.3.8.0 Now I would like to extend my project about the IIot Libraries SL package, I installed them. Next I added SMS_Service_SL 1.0.0.8 version library and I have problem with compile my project because I get error: [ERROR] PiXtend_DemoProject_q: Library Manager [Device: PLC Logic: Application]: Could not open library '#CAADTUtil'. (Reason: The placeholder library 'CAADTUtil' could not be resolved.) Any have idea what can I do to properly add SMS library to my project?
Last updated: 2023-09-26

Post by fabian on Sys Process Execute Command ^{CODESYS Forge talk (Post)}
Hello, I have a question: Once the command is being executed, is there a way to kill it again? As the called application is running in the background, the user can't close it but it shall be closed/terminated, commanded by codesys. I have tried with "SysProcessTerminate" but I guess this is not correct as the RTE crashes when this function is called. Starting the application: IF GVL.xStrtQR THEN GVL.xStrtQR := FALSE; SysProcess.SysProcessExecuteCommand2(pszCommand:=sCmd, pszStdOut:=stdout, udiStdOutLen:= SIZEOF(stdout),pResult := ADR(GVL.pResQRTsk)); END_IF Trying to stop it again: IF GVL.xTrmQR THEN GVL.xTrmQR := FALSE; pResTerm := SysProcess.SysProcessTerminate(hProcess:=SysProcess.SysProcessGetCurrentHandle(pResult:=ADR(GVL.pResQRTsk))); END_IF Codesyscontrol Win x64, 3.5.19.10. Many thanks for any advice pointing to the correct direction.. :-) Regards, Fabian
Last updated: 2023-11-17

Post by naks on Change IP address from IEC code ^{CODESYS Forge talk (Post)}
Hi, I'm working with wago 750-8212 controller. I want to change the IP address of the Ethernet adapter from webvisu. I have read some other threads in this forum and I have tried the following: Added the following text to the config file CODESYSControl.cfg: [SysSocket] Adapter.0.Name="br1" Adapter.0.EnableSetIpAndMask=1 Used the below code : IF xUpdateEthernet THEN Ethernet.Enable := FALSE; Reconfig ( xExecute := TRUE, itfNode := Ethernet, eError => ErrorReconfig, xBusy => xBusy, xDone => xDone, xError => xErrorReconfigure); IF Reconfig.xDone THEN ErrorCode := Ethernet.UpdateConfiguredIPSettings(IpAddress := NewIp, gateway := newGateway, subnetmask := newSubnetmask); END_IF IF Reconfig.xDone OR Reconfig.xError THEN reconfig(xExecute := FALSE); END_IF Ethernet.Enable := TRUE; Reconfig(xExecute := TRUE, itfNode := Ethernet ); END_IF I could change the IP address but when i restart my Controller then the IP address resets to the original, Is there anything I have missed, what else can i try ? Thank you in advance.
Last updated: 2024-07-08

Post by wbj0t on Global variable access by Programms and Modbus Devices (attach device to bus) ^{CODESYS Forge talk (Post)}
Hi everyone. I use Raspberry Pi 4, one core codesys SL. I have a question about global variable access via programm when I glued the same variable to MODBUS SERIAL/TCP DEVICE holding register. So, the question: what behavior of this modifying? When I set "Always update variables (in bus cycle)" and set some task as bus for the Device, then in another task I cant change this varible (can, but immediatly the old value setted again). But the same things works with MODBUS SLAVE: again "Always update..." and master attached to some task, then I change variable in another task and all works. I cant set up my variables from retains file at PrepareStart event because of this behavior with MODBUS SERIAL/TCP DEVICE. Thanks, wbj0t.
Last updated: 2024-07-18

Post by hazarath on How extract JSONElement containing Array data ^{CODESYS Forge talk (Post)}
I want to extract each element of an Array. Can someone help me with this. When I use JSONElementToString (part of JSON Utilities SL), I am seeing output as "ARRAY" instead of actual data. Here is the JSON content that I want to read : { "value1Unit": { "units": "M" }, "data": { "stepSize": 300.23, "points": [6,8] } } I would like to read each item of the element "points" i.e. 6 and 8. Here is the code I used, // Reading the content as JSON reader ( xExecute := execute , pwData := ADR ( converted_value ), jsonData := jsonDataStorage ); // Get the JSON Element jsonDataStorage.FindFirstValueByKey( wsKey := fidKeyVar, diStartIndex := searchElem, jsonElement => jsonElement ); JSON.JSONElementToString ( element := jsonElement , wsResult := valueWstring ); The content of the output of valueWstring is shown as "ARRAY" instead of the array items i.e. 6 and 8 Please can someone help me.
Last updated: 2024-07-30

Post by eguerra on Error in ScriptingEngine Docs - create_pou() ^{CODESYS Forge talk (Post)}
In the ScriptingEngine documentation there seems to be an error (or missing information) in the ScriptIecLanguageObjectContainer part ( https://content.helpme-codesys.com/en/ScriptingEngine/ScriptIecLanguageObjectContainer.html#ScriptIecLanguageObjectContainer.ScriptIecLanguageObjectContainer ). The description of the function create_pou() doesn't specify the correct arguments requested, it only says create_pou(type: SpecialPouType) and a script using the documentation definition of the function will raise an error. I tried passing the function arguments similar to the ones specified for the create_dut() function and it seems to work fine: create_pou(name, PouType) , name : str UPDATE: The offline help has the correct definition IExtendedObject<IScriptObject> create_pou( string name, PouType type = PouType.FunctionBlock, Nullable<Guid> language = null, string return_type = null, string base_type = null, string interfaces = null )
Last updated: 2024-08-05

Post by micik on Download EtherCAT project on SoftPLC (ControlWin-V3 x64) ^{CODESYS Forge talk (Post)}
Hello, I have almost exactly problem already discussed here in this old thread: https://forge.codesys.com/forge/talk/Engineering/thread/03af9426eb/ However, this is quite old and I assume not completely relevant. In my case, I use v3.5.20 on windows 11, so Winpcap is no longer supported on newer OS. Also, this hint about adding entry to the .cfg file under ProgramFiles(x86) is also not relevant anymore. I guess, I need to add entry SysEthernet to this .cfg file: C:\ProgramData\CODESYS\CODESYSControlWinV3x64...\CODESYSControl.cfg like this one: [ComponentManager] Component.1=CmpTargetVisuStub Component.2=CmpWebServer Component.3=CmpWebServerHandlerV3 Component.4=SysCpuMultiCore Component.5=SysReadWriteLock Component.6=SysCpuBreakpoints Component.7=SysPipeWindows Component.8=SysEthernet But I'm not sure about Npcap vs WinpCap. Please, if applicable, update these instructions.
Last updated: 2024-08-08

Post by alimans on OPC-UA Server, Symbol Set: Raise an error: Object reference not set to an instance of an object. ^{CODESYS Forge talk (Post)}
Hi everyone, I just created a very simple library without any code and, added it to my very simple project. after adding this library, I get an error when I try to open "Symbol Set" in "OPC UA Server" in "Communication Manager". Here is the code of my POU in the library: FUNCTION_BLOCK POU VAR eCommand : (CMD_NONE:=0, CMD_RESET:=-1) INT := CMD_NONE; END_VAR Attached is the error that I get. I also noticed that by removing the enumeration variable above (eCommand), I can open the "Symbol Set" again. Anybody has any idea why this error is raised and how could I use enumeration variables without error in "OPC UA Symbol Set"?
Last updated: 2024-08-08

Post by abner on Open specific Version of Codesys Control Win V3 x64 ^{CODESYS Forge talk (Post)}
Hi, I have installed different versions of Codesys, 3.5.7 - 3.5.8 - 3.5.16 - 3.5.19. When I create a project in Codesys 3.5.16 and I try to open an instance of Codesys Control Win V3 x64 it always open version 3.5.19, so appear a message windows about versions of devices are different. I have tried to open it from the installation folder and always open the last version 3.5.19 C:\Program Files\CODESYS 3.5.16.0\GatewayPLC C:\Program Files\CODESYS 3.5.19.70\GatewayPLC Does somebody know how to open an specific version of Codesys Control Win V3?
Last updated: 2024-08-21

Post by damian177 on Problem with downloading OPC UA tags by Data Source Manager ^{CODESYS Forge talk (Post)}
Hi, In Codesys V3.5 SP20, using Data Source Manager I am trying to connect to the OPC UA server and receive tags from it. The connection is ok, but the Codesys have a problem with downloading Tags group. The window (downloadingTags.jpg in attachement) never stop. After waiting for a while, I disconnect the connection and only the Server group remains downloaded, with OPC UA server diagnostic data (and this is read in Codesys). Of course, I tried connected via another OPC UA client : UaExpert , and everything works as it should, all tags are downloaded (Uaexpert.jpg screen). Has anyone on the forum encountered the OPC UA client configuration in Codesys? Is it possible to manually request the appropriate tags from the OPC server for reading in Codesys?
Last updated: 2024-09-03

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 Communication between applications on same device/controller/runtime (Win RTE 3.5.20.20) ^{CODESYS Forge talk (Post)}
If you have a Windows system (RTE), then why not run the CODESYS HMI as separate controller. This could easily be moved to another PC if required. In the HMI you could also still use the Symbolic Var access as part of the Data Source Manager, although maybe OPC is the preferred way to make it more future proof. Or what about the Remote Target Visu. Then you can reduce the load of the main controller, while still only having to create one application including Visualization. This is now also supported for Linux systems. See: https://content.helpme-codesys.com/en/CODESYS%20Control/_rtsl_target_visu_for_linux.html https://content.helpme-codesys.com/en/CODESYS%20Visualization/_visu_execute_remote_target_visu.html
Last updated: 2024-09-28

Post by bjarne-pagaard on OPC UA Server Status on Win RTE ^{CODESYS Forge talk (Post)}
Hi there, An "OPC Expert" client software is connecting to a Codesys Control RTE (x64) OPC UA Server. It reads only about 25 variables every 5 minutes. The OPC UA Server seems to shut down on the Codesys runtime. Is there any way to get information about the Codesys OPC UA Server status? Restart it? There is nothing in the PLC Logs after the OPC UA Server has started. It works for a while, then it doesn't. Any ideas? Any way of getting more info out of the Codesys OPC UA Server? -Bjarne
Last updated: 2024-10-21

Post by ofey on OPC server crash ^{CODESYS Forge talk (Post)}
Hi! I repeatly encounter a crash of the OPC server, which forces a reboot of the controller with frequent connect/disconnect to the server. Have any of you encountered this before? And is it a workaround? ie. deny that particular client connection by timeout or similar instead of crashing the PLC? This is during a development phase of the user interface. Up to 3 others connect/disconnect frequently to test their code. It is a bit troublesome of the PLC crashes several times a day because of this :( I greatly appreciate all comments. I hope it exists a fix for this, or something that hinders the crash. I attached the logfile for the crash
Last updated: 2024-11-26

Post by cihangur on OpC UA server on Raspberry Pi 64 SL runtime ^{CODESYS Forge talk (Post)}
After my tests, I noticed two issues. 1- WinCC disconnects the connection after receiving the GetEndPointResponse message from CoDeSys. (I found it with UAExpert and Wireshark.) 2- It establishes a connection despite waiting for a while on the network with DNS. As a result of this information: I solved the problem by adding the line "193.193.193.150 t9pac" to the C:\Windows\System32\Drivers\etc\hosts file and making Windows accept messages coming from the IP number 193.193.193.150 as coming from t9pac. (t9pac is the name of my PLC running CoDeSys.) If there is a setting that will allow CoDeSys OPC UA to respond to GetEndPointRequest with its IP address, this problem will not occur.
Last updated: 2024-12-12

Post by trusty-squire on Strange problem with the ‘MC_SetPosition’ function ^{CODESYS Forge talk (Post)}
How are the servo drives controlled? EtherCAT, step/dir pulses, other? Another thought is that - if it's step/dir pulse based control - the pulses from the PLC to the drive are getting missed/lost at high frequencies? If that's the case then there would be multiple troubleshooting steps/corrections that could be investigated. You could try to create a simplified program, with all the same parameters, that only has an MC_SetPosition FB you manually trigger and see if you are still getting the same results? When you manually control the motor directly from the servo drive software at the speeds you are calling for, does it move precisely to the target position?
Last updated: 2025-01-18

Post by mkintegration on Reading Absolute Encoder Position From Yasakawa Drive ^{CODESYS Forge talk (Post)}
I am looking to read in the absolute position of a yaskawa servo drive Sigma 7 that is using absolute encoder. It looks like yaskawa outputs this across there CN1 I/O connecter and during operation just outputs encoder pulses. But at boot up transmits the Multiturn data position and the Position within one rotation (pulse train) on two different wires. Once the drives are enabled it just uses incremental pulses. Does any one have experience with what IEC blocks to use to read this information in. I attached the Yaskawa Manual section that talks about the format.
Last updated: 2025-02-26

Post by mkintegration on Reading Absolute Encoder Position From Yasakawa Drive ^{CODESYS Forge talk (Post)}
I am looking to read in the absolute position of a yaskawa servo drive Sigma 7 that is using absolute encoder. It looks like yaskawa outputs this across there CN1 I/O connecter and during operation just outputs encoder pulses. But at boot up transmits the Multiturn data position and the Position within one rotation (pulse train) on two different wires. Once the drives are enabled it just uses incremental pulses. Does any one have experience with what IEC blocks to use to read this information in. I attached the Yaskawa Manual section that talks about the format.
Last updated: 2025-02-26

Post by struccc on Problem Reading Registers via Modbus from non Codesys device ^{CODESYS Forge talk (Post)}
Hi, Might be a good idea first to try out the connection and the device with some handy software, like Modbus Poll. There you can see better, what's really going on... - Is it really connected? - What error code does it return? - Can it read from the register address? - Maybe try Input registers and Holding Registers - can make a difference - Sometimes register addresses are messed up: shifted +-1 (mixing of 2 standards) - Sometimes register addresses start with offset 30000, 40000 ... - Are you using the right protocol? - Is it RTU or TCP? Maybe ASCII? - Can even have a look at the data packets, etc... All this is easier to figure out first with some modbus utility... and then to set it up in CODESYS should not be an issue. P.
Last updated: 2025-03-09

Post by mehakfatima on Need Help Configuring Energy Analyzers via Modbus TCP & RTU (RS-485) in CODESYS 3.5 ^{CODESYS Forge talk (Post)}
Hello everyone, I am currently working on reading data from energy analyzers using Modbus TCP and RTU (RS-485). In my previous software, I used the following method to add slave devices (i have attached the image) and configure registers: Add the Modbus slave device. Configure the communication parameters (baud rate, parity, etc.). Define the registers and their addresses for data retrieval. Now, I am trying to achieve the same in CODESYS 3.5, but I am not sure how to configure the Modbus master, add slave devices, and set up the registers properly. If anyone has experience with Modbus TCP/RTU setup in CODESYS 3.5, I would really appreciate your guidance! A step-by-step explanation or any references/tutorials would be extremely helpful.
Last updated: 2025-03-13

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