Post by manuknecht on Persistence Manager does not save alphabetically first value ^{CODESYS Forge talk (Post)}
I have several libraries which contain values that should be saved on a PLC. As apparently no Persistent Variable List is available within Libraries, I use the Persistence Manager to create a Persistence Channel in the Project which imports the library. I then specify the persistence channel in the library using the {attribute 'ac_persist':='PersistenceChannel_CT'} specifier. This generally works very well and gives me exactly the properties I require. However, it came to my attention that the (alphabetially) first value from the library is not saved in the created ASCII file. When checking the content of the Persistence Channel, it shows all the variables as defined in the library. But the created file does not contain the first value and it is not restored after restart or reset. (see attached picture) I disabled Periodic Saving and set xSaveOnChange to TRUE and so the file usually updates immediately after changing one of the values. When changing the first value, it does not update which is consistent with this value not being saved. I also created a sample project and library from scratch which shows the same issue both using a Raspberry Pi and using a Linux machine. Does someone know what the reason for this could be or did someone make similar experiences? Looking forward to hearing your suggestions. Thanks in advance and best wishes Manuel
Last updated: 2023-10-17

Post by jschu on Dynamical scaling of bar graph without the bar itself ^{CODESYS Forge talk (Post)}
Hi there, Task: dynamical changing the scaling of an bar graph, linear scaling whitout showing the bar only the scaling values and Lines for Main and partial steps. Define 4 Limits for Hi and LO Values with different colors Option 1 : use the bar graph whitout showing the actual bar whitout showing the bar, only the scaling values and lines for main and partial steps. Then what to do with the 4 Limits ? I could use 4 moveable Rectangles with the start and end value fo the areas but then the whoel bargraph must be transparent. Best way would be if only the scale ist possible to show as it is possible for the Meter 180° but this option does not exist for the bargraph. Option 2 : user defined HMTL5 Widgets wich may be some allreay has created or where is a dome for using this kind of html5 widget. The expanse for use html is in my eyes to big and gives more option for errors. Have some one experience in this topic or a hint how to do it the easiest way? Thanks for your help.
Last updated: 2025-05-15

Post by abuckie on i2c master not running ^{CODESYS Forge talk (Post)}
Hello, I am trying to create an Ethernet/IP device that can read analog signals, do some basic logic on it and then hand communicate the results to an Ethernet/IP master. I am using the Raspberry Pi to experiment with this as I would ultimately like to drive a display as well. I have loaded up the runtime on the Pi and got the digital I/O working. I have an ADS1115 ADC to I2C board and I can't get it to work, I get a message telling me the i2c master is not running and I am not sure where to start with this. Is there a manual for running CODESYS on the Pi or something like that I am missing? I found this post and opening the project in CODESYS V3.5 SP21 it seems like tons of this wouldn't convert properly https://forge.codesys.com/forge/talk/Runtime/thread/f1400b71b6/ I have added in the library and device manually and copied the structured text program but lost at what to do if the core functionality of the master is not running. I appreciate any help, thanks.
Last updated: 2025-05-19

Post by timvh on Codesys virtual control redundancy ^{CODESYS Forge talk (Post)}
I think it depends on what you consider as redundant. Is it allowed to plug the network cable in another device (server), move the USB key with license to the other device (server) and then start it up? Or should it automatically switch over within msec and take over the communication with the I/O flawlessly without noticing the switchover? We helped several customers setting up the CODESYS Redundancy functionality and the nice thing is that when you have it up and running, you can easily switchover from active to passive and when you download a new applicaiton, CODESYS handles the update of boot project on the passive controller automatically. Sure this will require an additional license and the license for redundancy, but if your installation is that critical it should be worth it. Please contact us (Extend Smart Coding) if you need any further information. We could help you setup the configuration and possibly provide the licenses for it (I noticed you are situated in the Netherlands).
Last updated: 2025-09-04

Post by vahasa on CAN TPDO / RPDO ^{CODESYS Forge talk (Post)}
Hi I'm automation engineering student and I'm not yet quite familiar with CAN-bus. What I am trying to achieve, to send two byte message via CAN from Epec display to Scott Drive inverter. I'm using code template made with Epec Multitool in Codesys 3.5 Problem i'm facing is that drive responds with same COB-ID. In multitool, you can create TPDO/RPDO. And depending on that, display either sends or only receives. This is problem, because for parameter polling from drive, you need to send two byte request to 0x399 and drive responds with eight bytes. If request is longer, drive don't respond. 0x399 is currently setted as RPDO, so display doesn't send anything on startup and I made program that sends messages to 0x399 bytes 0 and 1 and bytes 3-7 are shown in display. If setted as TPDO, display send all eight bytes and therefor drive cannot respond. But, I think because they are defined as RPDO, display won't send message, although monitoring with Codesys, values are changed. Question is, how should COB-ID be configured in Codesys, so it wouldn't automatically start to send message but would send when needed?
Last updated: 2023-12-19

Post by dominggus on when going online, stuck on "Syncing file "visuelemsdatetime.tl_datetime.txt" ^{CODESYS Forge talk (Post)}
Hi, We are currently using a Raspberry Pi 4 CM4 module in a EdgeBox RPI 200 - Industrial Edge Controller running the latest CODESYS Runtime Package 4.11.0.0. On the PC (actually an Intel Macbook Pro running Windows 10 in Parallels) we run CODESYS V3.5.19.50. Yesterday end of day when I was about to logoff and head home, I wanted to send the latest build to the Raspberry I clicked the Login button to compile a new version and then sync the application and all the files, it get's stuck on the last file to sync (see attached screenshot). This takes eternally, although sometimes, when I use my SFTP client (Cyberduck) and go into the raspberry and refresh the directory /var/opt/codesys/PlcLogic/visu/, or when I open the actual file visuelemsdatetime.tl_datetime.txt, it gets un-stuck (forcing a refresh, which might fix the syncing issue) and CODESYS continues and I can click the Start button to start the application. But this SFTP force refresh trick does not always help either... What could be the issue here? network connectivity? Can someone please help me out?
Last updated: 2024-03-02

Post by andrea199403 on Assigning Modbus addresses to a structure in a dynamic way ^{CODESYS Forge talk (Post)}
Hello everyone, I am new to this forum and I am also new to Codesys programming. My problem is this: I have a STRUCT of 64 bool and 30 real, this STRUCT is assigned in the programme 9 times. Now I need to communicate with an HMI via Modbus and I have defined the slave device and created the holding registers for communication. I would like to declare the first call of the STRUCT on the Modbus registers %QX2000.0 to %QX2007.7 for the booleans and on the registers %QW1004 to %QW1034 for the real registers. That said, I would like to change an index and set an offset of 100 bytes for the calls of the other 8 assignments, so that the result is: %QX2100.0 to %QX2107.7 for the booleans and on the %QW1104 to %QW1134 registers for the Real registers, etc. Is there a way to declare this? Thank you very much.
Last updated: 2025-10-21

Post by farren on How to stay in a method until something is finished. ^{CODESYS Forge talk (Post)}
I know I'm thinking about this wrong -- too many decades of procedural and event-driven programming and only a few months of PLC ST programming...... I've created a visualization with a button that when pushed calls a method. I want the method to take a pressure reading, wait one minute and then take another pressure reading. I'm looking for leaks. I'm using TON for the delay. It seems like what is happening is that the method gets called once and it takes the first reading and starts the TON. But then execution continues, leaves that method call, and the second reading never happens. I can force the method to keep running until the whole thing is done with a While loop, but I understand that is considered BAD in PLC programming. If it push the button again to call the method again, it picks up where it left off and if the timer is complete then it runs the remaining code. How do I keep that method running until it is complete with just one call without using a while loop that ties up the PLC for a minute? Thanks! -Farren
Last updated: 2025-10-31

Post by mohammedben on Fail communication between CODESYS and Fuxa SCADA via OPC UA ^{CODESYS Forge talk (Post)}
hi, When I try to establish communication between CODESYS and Fuxa SCADA via OPC UA, the connection fails, and I receive the following error: 2026-02-15T08:38:13.618Z [ERR] 'codesys' connect failure! Error: The connection may have been rejected by server, Err = (ClientTCP_transport6: socket has been disconnected by third party) 2026-02-15T08:38:13.619Z [ERR] 'codesys' try to connect error! Error: The connection may have been rejected by server, Err = (ClientTCP_transport6: socket has been disconnected by third party) 2026-02-15T08:38:13.622Z [ERR] 'codesys' connect error! undefined (1) Note that there are no problems when I establish communication with the UaExpert and OPC UA Client Simulator software. I also previously tried communicating with RapidSCADA and received the following error: Endpoint with the specified security options not found. And when I try to connect with "none" in the security policy, I get this error: BadSecureChannelClosed I have tried almost all the solutions available online and have not found a solution. I hope you can provide me with a solution that solves this problem. Thanks in advance
Last updated: 2026-02-16

Post by baltzer on ICertificateVerifier.VerifyCertificate doesn't appear to override an ERR_CERT_HAS_EXPIRED rejection in TCP_Client.Upgrade() ^{CODESYS Forge talk (Post)}
Setup: Net Base Services (NBS), TCP_Client + TLSContext, ePurpose := CLIENT_SIDE, connecting to a third-party embedded device (Velux KLF200 home automation gateway) whose factory-installed TLS certificate expired on 2026-07-12 and has no user-facing renewal path. Tested on both CODESYS Control for Raspberry Pi SL (3.5.19.0) and CODESYS Control Win V3 x64, with identical results on both. Goal: Accept the peer's expired certificate via a custom ICertificateVerifier implementation, since the certificate itself can never be replaced. Implementation: FUNCTION_BLOCK FB_MyCertVerifier IMPLEMENTS NBS.ICertificateVerifier VAR udiCallCount : UDINT; aeCurStateLog : ARRAY[0..9] OF NBS.RTS_IEC_RESULT; END_VAR METHOD VerifyCertificate : UDINT VAR_INPUT hCert : NBS.RTS_IEC_HANDLE; eCurState : NBS.RTS_IEC_RESULT; END_VAR IF udiCallCount < 10 THEN aeCurStateLog[udiCallCount] := eCurState; END_IF udiCallCount := udiCallCount + 1; VerifyCertificate := 0; // also tried: VerifyCertificate := eCurState; Wired in via tlsContext.itfCertVerifer := certVerifier at declaration time, alongside itfTLSContext := tlsContext set at TCP_Client's own declaration (per an earlier forum thread here on ensuring inline start-values on FB-typed variables are actually honored when nested one level deep - that fix was needed and worked correctly for getting the handshake to start at all). Observed: - VerifyCertificate is confirmed called exactly once per connection attempt (via the call counter above). - eCurState passed in = 0x709 = ERR_CERT_HAS_EXPIRED - correctly reflecting the actual state of the peer's certificate. - Packet capture confirms the full TLS 1.2 handshake completes correctly at the wire level: ClientHello -> ServerHello -> Certificate -> ServerKeyExchange -> ServerHelloDone -> our ClientKeyExchange/ChangeCipherSpec/Finished -> server's ChangeCipherSpec/Finished. Both sides successfully complete the cryptographic handshake. - Despite this, TCP_Client.Upgrade() subsequently returns NBS.ERROR.CONNECTION_ERROR, and the connection is torn down with a plain TCP FIN (not a TLS alert) roughly 7-8ms after our side ACKs the server's Finished message. - TCP_Client.eErrorID (inherited from LCon) remains NO_ERROR throughout - the failure is only visible via Upgrade()'s return value. - Returning 0 (ERR_OK/ERR_CERT_OK - confirmed via the CmpErrors2 Interfaces documentation that these are literally the same value) makes no difference. - Echoing eCurState back unchanged (on the theory that this callback might work like mbedTLS's native verify callback, where the incoming state is a flags value to be cleared/modified and returned, rather than paired with a separate fixed "accept" sentinel) also makes no difference. - Identical result across udiVerificationMode := 0, 1, and 2. - Importing the peer's certificate into the runtime's trusted certificate store via cert-import trusted makes no difference either. - With itfCertVerifer left at its default (no custom verifier) and udiVerificationMode := 2, the underlying engine sends its own fatal TLS alert (handshake_failure) immediately after receiving the peer's Certificate message - suggesting built-in validation may reject at the record layer independent of whether a custom verifier is even present. Questions: 1. Is there an additional step required for a custom ICertificateVerifier to actually override an ERR_CERT_HAS_EXPIRED (or more generally, any ERR_CERT_*) rejection, or is certificate validation enforced unconditionally for a CLIENT_SIDE TLSContext regardless of what the verifier returns? 2. Is 0/ERR_OK genuinely the correct "accept" return value for VerifyCertificate, or does it expect something else (a specific bit pattern, a different constant, a value that must be computed from hCert itself)? 3. Is there a supported way to connect to a peer presenting a certificate that is both self-signed and expired, short of the peer issuing a new certificate? Happy to share the full packet captures or additional test combinations if useful. Also worth noting for anyone finding this thread later: a maintained Node-RED library for this same device (node-red-contrib-velux-klf200, forked to handle this exact expired-certificate situation) solves it by disabling built-in TLS validation entirely (rejectUnauthorized: false) and doing fingerprint-based pinning by hand after the handshake completes, rather than relying on a validation callback - which may be the more realistic approach here too if ICertificateVerifier genuinely can't override this class of rejection. Thanks in advance /Jørgen Disclosure: most of the CODESYS code and this investigation was developed with the help of Claude (Anthropic's AI assistant) - the state machine design, SLIP/checksum implementation, and debugging methodology (including the packet capture analysis) were worked through in an extended back-and-forth with it. Posting here because we've run out of self-serviceable options and this now looks like it needs input from someone with visibility into NBS's actual implementation.
Last updated: 2026-07-26

Post by yannickasselin on MQTT QoS 1 & 2 ^{CODESYS Forge talk (Post)}
Hello, I am using Codesys sp20p3 and IIoT library 1.11. I am trying to test QoS 1 & 2 and I have some issues. I am using mosquitto as the broker. I am also using some other MQTT clients like Node-Red and TwinCAT. They all work as expected for every QoS levels. I only have issues with Codesys MQTT client. In the Codesys client, if I subscribe to a topic as QoS 1 or 2, and a client publishes to this topic, I receive the message. But if I disconnect the Codesys client from the network and a client publishes to the subscribed topic, when I reconnect Codesys client to the network, I don't receive the messages as expected. Also there does not seem to be an auto-reconnect feature. So I have to manually set the mqttClient.xEnable bit to FALSE then back to TRUE in order to reconnect to the broker, then I also have to set the subscribe.xEnable to FALSE and back to TRUE in order to re-subscribe to the topic, but even then, I don't receive the messages that were published while I was disconnected. What am I doing wrong? I set the cleanSession bit to FALSE and I give my client a clientID. With the TwinCAT MQTT Client, I do the same thing and everything works as expected. It even auto-reconnects to the broker. I would expect Codesys MQTT Client to be as reliable as TwinCAT. Maybe I am doing something wrong? I also noticed that when trying to publish a QoS 1 or 2 message while disconnected from the broker, it does not work. In TwinCAT, I am still able to publish. The messages are stored in the client and published once reconnected to the broker. I would expect to be able to do the same thing in Codesys. Is this all possible? Am I doing something wrong? Thank you
Last updated: 2024-10-26

Post by yannickasselin on MQTT QoS 1 & 2 ^{CODESYS Forge talk (Post)}
Hello, After some more tests, here is what I found out. It seems we have to increase the uiKeepAlive and tPingInterval parameters. If I increase the uiKeepAlive value to 60s and the tPingInterval to 30s, then if I disconnect the ethernet cable from Codesys and publish some messages to which Codesys subscribes to and then reconnect within 30s, I will get the messages. If I don't reconnect the cable within 30s (ping interval), the client goes in error with "ACKNOWLEDGE_TIMEOUT". When this happens, it will not automatically reconnect after reconnecting the cable. I have to disable and re-enable the client but I will not get the published messages. I need to do more tests because there are a lot of weird things happening when playing with the ping interval and the keep alive. It is not clear to me what does what. I even ended up not receiving messages anymore, even if I disabled and re-enabled the mqtt client. The client did not give any error. The only way I was able to get messages again was by modifying my client ID. After that, if I try to re-use one of the old client IDs, nothing works (publish, subscribe) and I get a TCP_INIT_ERROR and sometimes a TCP_READ_ERROR. I need more explanation/documentation about these weird behaviors. Maybe it is the way I use it, maybe it is related to the broker (I am using Mosquitto with default parameters). When using a Node-Red client, everything works perfectly. I am trying to achieve the same behavior with Codesys but it seems impossible so far.
Last updated: 2024-10-30

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 mmoncada on Dinamically loading recipes ^{CODESYS Forge talk (Post)}
I'm having trouble with the initial loading of recipes. I can create them and load one or the other, but when the program restarts the recipes are not listed. I'm calling: RecipeManCommands.ReloadRecipes and then RecipeManCommands.GetRecipeCount which returns 0 recipes. None of the methods returns error and if i call them again after RecipeManCommands.CreateRecipe RecipeManCommands.ReadAndSaveRecipe getRecipeCount returns the number of recipes created. When i restart the system, once again they are not listed even though the recipe files are there. Any ideas? Martin Btw, Codesys 3.5 SP 16 Path 9
Last updated: 2023-12-06

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 mini-developer on Profinet Exor connection drop ^{CODESYS Forge talk (Post)}
Hello, I have a Exor HMI with 2 seperatred ETH interface's. It is Configured as PN Master on ETH interface 1 and the IO's are working, as long as the development PC is connected to the ETH 0 interface. When the PC is disconnected, the PN communication drops and a reconnection is started. I installed the newest device description for Codesys and Firmware for the Panel. The IO Gateway is from Weidmueller What could cause the Problem?
Last updated: 2024-10-16

Post by vincentger on using ADS1115 ^{CODESYS Forge talk (Post)}
Any reason the ADS1115 wouldnt work with SP20.1 and Runtime 10.0.0.0 on the Raspberry Pi . Using Bullseye or Buster i run into the same issue: Libary and integration works in general as described above BUT i am seeing "bleeding" between the analog inputs . Specifically consecutive ones: So sometimes the raw from AI1 shows on AI2, AI2 on AI3, .. AI4 on AI1. Even with filtering i cant smoothen that out properly and i feel like something is wrong. Almost like the bus is stumbling over itself, or the request from Codesys to the device.
Last updated: 2024-10-28

Post by pernockham on Persistence Manager: Config File not found? ^{CODESYS Forge talk (Post)}
Trying to utilize the persistence manager, but system do not write to file and do not create the config file. System is a Linux SL, version 4.13.0.0 Problems with persistence/config started when I had other problems to go online, I deleted the config file and the persistent files, but the system will not re-create them. I have tried to remove/re-install the "PersistenceManager"-module, create the folder-structure myself. And also reinstall the linux-runtime but its clearly not working. Any help appreciated.
Last updated: 2024-10-31

Post by varshag on Trying to pull Logged In user details and certain other variable values and in turn log to a database ^{CODESYS Forge talk (Post)}
Hello All, I am new to Codesys and am trying to create a simple project which would let me log to a 6 column database table. I can use a push button on Visualization to initiate the logging. Column 1:Timestamp Column 2:Full name or Initials of Logged in operator Column 3,4,5,6: Certain variables Any help is highly appreciated. Thank you.
Last updated: 2024-11-07

Post by garrian on How to write multiple coils (Modbus FC15) ^{CODESYS Forge talk (Post)}
Thanks! As far as I can see, the client can only send words. And on the server side there are an array for each of the functions: bool for coil and discrete, word for holding and input registers. I assume I can use holding register, then use bit mapping on the words instead of coils. But I really want to use the FC15/coils.
Last updated: 2024-11-17

Post by dogulas on Removing a symbol from the IEC Symbols Editor grid ^{CODESYS Forge talk (Post)}
In the CODESYS IDE I have several symbols defined and I have IEC Symbol Publishing installed. On the IEC Symbol Publishing window and under the IEC Symbols Editor tab, I have dragged symbols from the tree on the left to the grid on the right. All this works fine. Now I want to remove one of the symbols from the grid on the right and I cannot see any way to do this. How can I remove a symbol from the grid on the right once I've added it?
Last updated: 2025-02-07

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

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