Post by tehthoams on Find Function: Object reference not set to an instance of an object. ^{CODESYS Forge talk (Post)}
Hey, Sorry this isn't super helpful, but i had this problem once and was able to resolve it. I can't recall how I solved it and whether it was a problem with my codesys installation or the project itself. If it is the codesys installation, make sure all your required libraries and plugins are installed and available. compare with a colleagues installation if possible. I vaguely recall saving a copy of my project and deleting things one by one until the error went away...
Last updated: 2023-10-30

Post by davidbo on All the things needed for anonymous login to OPC UA ^{CODESYS Forge talk (Post)}
When you have a deep object structure where not all values are not exposed to OPC UA, the top object will not have a V check mark but be filled fully out. In that case CODESYS do not always registrate changes to inner object. Solution set a V in the checkbox of the top object, build, download. Now you can browse, but all values in the top object will be selected, then you can deselect the ones you don't want, build, download and it works
Last updated: 2025-09-10

Post by wind-11 on Problem with simulation Modbus ^{CODESYS Forge talk (Post)}
Hello everyone, I encountered a problem in the simulation while working. In a test project we set up a Modbus connection. We wanted to simulate this with test values. The connection also worked, but unfortunately the values are frozen and do not report any “current data”. (Picture attached) Since these are my first points of contact with Codesys and my colleague continues to work elsewhere, I was hoping that someone here might have an idea. Kind regards and thanks in advance.
Last updated: 2024-03-22

Post by dkugler on Codesys SVN ^{CODESYS Forge talk (Post)}
Don't set on SVN. The service phase has started in March 2024 and will be discontinued in 2027. We actually use SVN and have to switch to GIT in the future. As I informed, there is no way of getting a single SVN or GIT licence. I' dont understand, why Codesys forces us customers to pay for an expensive Professional Edition paket from year to year using only one part of it! If you find a way to buy a single licence, let me know.
Last updated: 2024-04-29

Post by appling on License status of Linux 64Bit runtime via CLI ^{CODESYS Forge talk (Post)}
Hi, I have a Linux 64Bit system with a Codesys application running on it. It stops after 2hours and a few minutes, which makes me think something is wrong with the installed license. (in my last timing it stopped after 2h4min, on the codesys website it is stated that runtimes without a license stop after 2h) I installed the license via a USB license dongle that I activated on my workstation with the Codesys IDE a while ago. Now the system is shipped at not accessible physically, only remotely via SSH. So is there a way to check the status of the License of the Codesys runtime when it is running on the system? Running the codesyscontrol script with "status" just tells me that it is running, but does not provide any license information. Best regards
Last updated: 2023-12-04

Post by mark on IO link on IFM AL133x only single digital input on a channel ^{CODESYS Forge talk (Post)}
I have a problem with the CODESYS IO-Link SL software. When I insert a IO link master AL1332 and plug a discrete digital input to a channel it reads only 1 of the 2 available inputs on that channel. Is there anyone who sorted out if the second input is also usable? When we configure the module without the CODESYS IO-Link SL software then the second input on the channel can be used. At the moment we use some channels on a module as IO-link port, and some as discrete IO. It would be very nice if we can use both inputs on a channel with the use of CODESYS IO-Link SL.
Last updated: 2023-12-18

Post by alexgooi on Function Blocks and arrays of function blocks ^{CODESYS Forge talk (Post)}
Hi Jack, I think you have to look at a FB in a different way. A Function block (Class) can contain its own data. In other words don't define loose data in your GVL, but define a instance of a FB (Object) in your GVL: Example: Function_Block Basic_Class VAR_INPUT Open_Command: BOOL; END_VAR VAR_OUTPUT Opened: BOOL; END_VAR if Open_Command then Opened := TRUE; ELSE Opened := FALSE; END_IF Global Variables Objects: ARRAY[1..100] OF Basic_Class; //Here you ar defining you objects END_VAR In your code you can directly acces the data and couple it to the IO: GVL.Objects[1].Open_Command := %IX0.0; %QX0.0 := GVL.Objects[1].Opened; //To call the code itself use: GVL.Objects[1](); If you want to take this a step further you are also able to add methods and properties to the FB/Class end thereby creating a OOIP program
Last updated: 2024-02-15

Post by dhumphries on Deploy Codesys Control SL to a 'secure' device ^{CODESYS Forge talk (Post)}
I have the same problem on a setup where I'm trying to load control SL onto a fresh installation of ubuntu server 22.04 (with sudo privileges,) I've done this in the past several times but only with codesys 3.5.19.x since updating to the new versions I'm having inconsistencies, either I can load the runtime but not login or I can't load the runtime at all. I appreciate there are new releases frequently, but it would be nice if there was a LTS version with some kind of documentation. I'm currently building a VM so I can install version 3.5.19.4 since this was the last version that worked for me. Adding additional versions through codesys installer has been unsuccessful, hopefully a fresh install on a virgin OS will be more successful.
Last updated: 2026-08-10

Post by taqamert on Codesys 3.5 Library Download Failed ^{CODESYS Forge talk (Post)}
Hello, I need a few libraries in CoDeSys 3.5. I want to download them using the "Download Missing Library" option from the Library Manager menu. However, I keep getting a "Download Failed" error. Despite trying at different times, I haven't been able to download them. What should I do?
Last updated: 2024-08-21

Post by dkugler on User management ^{CODESYS Forge talk (Post)}
If the PLC is equieped with a USB socket it's possible to copy the user management file via IEC code to a USB stick and restore it at the new plc. The file is located there: /PlcLogic/visu/app_visuusermgmtdb.csv I use this to reset the user management to default in case of the customer has changed passwords and lost it.
Last updated: 2024-09-04

Post by tyronnosaurus on SysLibMem.lib Where To Download? ^{CODESYS Forge talk (Post)}
It should come by default on a normal install of Codesys 2.3, but it's a bit hidden: Like for any other library, go to Resources > library Manager > Right click on list of libraries > Additional library. On the browser that opens, instead of looking in the default folder, use the dropdown menu at the bottom to change the folder (SysLibMem should be on the 3rd folder).
Last updated: 2024-11-11

Post by ganassa on Custom colors in Ladder diagrams? ^{CODESYS Forge talk (Post)}
How can I change the default color - blue - for active lanes, contacts and coils? I'd like a lighter color. After having failed in finding a related option in the IDE, I've looked at the "Default.editortheme" file in CODESYS' directory, but couldn't see any related option. Thank you
Last updated: 2025-07-09

Post by fredsta on Unable to load dynamic modules (Download failed: Application=Application) ^{CODESYS Forge talk (Post)}
I'll have a look at this, thanks. Do you maybe know why the C-integration doesn't work? I'm just curious because it was still some effort to create all these files. Ending up with a meaningless error feels very unsatisfying to me...
Last updated: 2024-02-19

Post by matt-purcell on Which Lib to use, connect to a socket with URL instead of IP address ^{CODESYS Forge talk (Post)}
I've been searching through these libraries, syssocket and net base services and they all seem to use the same structure for IP address for the connect function, SOCKADDRESS. At a glance, it doesn't look like that'll work, maybe it's just missing in the documentation somewhere?? I'm wondering if anyone has done it.
Last updated: 2024-06-17

Post by antonz on Could not write options file at... ^{CODESYS Forge talk (Post)}
I ran into a similar issue, albeit not the exact same conditions nor the same file if I recall correctly. As a workaround I have used an elevated account to give my regular user account write access to the specific directory where the failure occurred. It is not pretty and I am not happy with it. It does work.
Last updated: 2026-09-07

Post by nikgind on Codesys Communication Manger - Required information model version exists in the model repository but is not found ^{CODESYS Forge talk (Post)}
Hi I am trying to import a custom information model that I created using UA Modeler. I have only added two new methods and two new object types. It is possible to add the information model to the Communication Manager and the two new object types are shown in the Information Model tab. After compiling i get the following error: Communication Manager [Device: PLC Logic: Application]: The information model http://opcfoundation.org/UA/ is required by http://yourorganisation.org/Bsp_3.1/ with a minimal publication date from 15.12.2023 but the device has only a model from 15.09.2021 installed. Probably the information model from 15.09.2021 is missing in the information model repository. The error message does not make sense to me. Should it not be “Probably the information model from 15/12/2023 is missing in the information model repository”? Anyway I have installed the information model from 15/12/2023 but not from 15/09/2021. Which makes the error message even stranger.
Last updated: 2024-06-09

Post by totorovic on Project loses 'Download time' information ^{CODESYS Forge talk (Post)}
I continue this topic by myself, I'm very happy with the Codesys support / community ;-) This information (Download time) should be stored in the compileinfo : https://content.helpme-codesys.com/en/CODESYS%20Development%20System/_cds_cmd_load.html But the file is not text-readable (see attached file) so how to solve if download time is empty?
Last updated: 2024-12-19

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 testlogic on Sending Sequential Modbus TCP Packets ^{CODESYS Forge talk (Post)}
I have a Modbus TCP slave device where I need to do sequential writes to the same register. The register I'm writing to is kind of like a command line, each packet is a command word encoded in Hexadecimal. I am having difficulty implementing this system in CoDeSys 3.5 SP19. I feel like the structure of the program should be something along the lines of (Pseudocode): ModbusTCPSend(Command Register, Command1) ModbusTCPSend(Command Register, Command2) ModbusTCPSend(Command Register, Command3) I have tried to implement this with a rising edge trigger wMot1OPCode := 16#E1; //Stop Motor & Kill Program xMot1SendOP := TRUE; //Send OP on rising edge xMot1SendOP := FALSE; //Reset wMot1OPCode := 16#9E; //Disable Motor xMot1SendOP :=TRUE; //Send OP on rising edge xMot1SendOP := FALSE; //Reset Where "wMot1OPCode" is the IO map for writing to the command register, and "xMot1SendOP" is the rising edge trigger for that modbus channel. However, this doesn't work. The device never responds to the modbus commands. It seems like the trigger variable is switched too quickly for modbus to send the packet. I know the modbus register is working, because I can set the channel to cyclic and the device will respond. However, I can't use this reliably because I need each command to be sent once, in order. Cyclic keeps re-sending the commands and seems like it could miss a command as well if one was sent in-between cycle time. I have also trying using the Application trigger as described by https://faq.codesys.com/pages/viewpage.action?pageId=24510480, but this is also not working for me. See attached picture for my FBD code. This seems like a simple function, I can't tell what I'm doing wrong here. Thanks for the help.
Last updated: 2024-03-06

Post by timvh on Sorting array of any-sized structure ^{CODESYS Forge talk (Post)}
Look all the way at the end of the link below. This provides a way to use arrays with various lengths: https://content.helpme-codesys.com/en/CODESYS%20Development%20System/_cds_datatype_array.html
Last updated: 2023-08-18

Post by fabian on Trace commands via Test Manager ^{CODESYS Forge talk (Post)}
Hello Yuridnb, Did you get any further with this project? I'm standing at a similar point and would like to hear from any experiences made so far. :-) Best regards, Fabian
Last updated: 2023-12-05

Post by eschwellinger on Using the Wago 750-658 CAN Gateway ^{CODESYS Forge talk (Post)}
I would ask the Wago Support - they have a CODESYS V3 runtime (not eCOCKPIT) which probably support this? At least worth to ask them.
Last updated: 2024-07-23

Post by i-campbell on Codesys 3.5 Library Download Failed ^{CODESYS Forge talk (Post)}
You use very old codesys, maybe SP13? the newer sp17 libraries are in a format not compatible with your version. I suggest upgrading everything to at least SP17, but may as well go to SP20 Patch 2.
Last updated: 2024-08-21

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