Post by ojz0r on INT_TO_WORD function not working ^{CODESYS Forge talk (Post)}
That calculation will not work the way you expect it to. If PumpFillSpeed is limitied to 0-50 then the only whole number would be 50/50 = 1 everything else is 0.0-0.9999... and since you are using word and integer only 50 would work since there is no representation for mantissa in integer values. Declare a temporary real variable and do the calculation and then do a REAL_TO_WORD in the DRV2Speed assignment.
Last updated: 2024-01-26

Post by thomas-moba on "sudo"-Befehle über die Funktion "SysProcessExecuteCommand2" ^{CODESYS Forge talk (Post)}
Hello, I need to execute "sudo" commands via CoDeSys 3.5 SP 19 P5 using the "SysProcessExecuteCommand2" function. Commands without sudo are no problem, but as soon as sudo is used in a .sh or a single command, it does not work. Command=AllowAll is entered under "SysProcess" in CODESYSControl.cfg. Nevertheless it does not work. Does anyone know what the problem could be? Greetings, Thomas
Last updated: 2024-02-01

Post by otdeveloper on IEC 61499 ^{CODESYS Forge talk (Post)}
It is being worked on by many companies and its even-driven function blocks seem like a natural evolution of the object oriented industrial programming I have seen Gary Pratt (author of the Book of CODESYS and much more) so expertly implement and explain. I would expect CODESYS to have this front and center on their sights and, if they do not, I would be very interested in learning why.
Last updated: 2024-02-09

Post by kleeswi on SysFileOpen does not work after update to V3.5 SP19 Patch 5 ^{CODESYS Forge talk (Post)}
I use the function SysFile.SysFileOpen(sFileNamePara, SysFile.ACCESS_MODE.AM_WRITE, pErrorFileOpen); to open and write a file. Since the update from Codesys V3.5 SP17 to V3.5 SP19 Patch 5 it does not work anymore. I first had SysFile.SysFileOpen(sFileNamePara, SysFile.ACCESS_MODE.AM_APPEND_PLUS, pErrorFileOpen); in both versions. hFile_Test is a pointer to byte. It gives an exceptional error when dereferencing the hFile_Test pointer. Edit: I use Codesys on a Raspberry pi
Last updated: 2024-02-19

Post by andrej on POU - Access to runtime ^{CODESYS Forge talk (Post)}
Hello all, when creating a POU, the Codesys IDE allows the setting "Enable System Call" (in the Settings, Property -> Build), see picture. The name suggest, that runtime functionalities i.e. functions of codesyscontrol such as "stop plc" etc. can be directly called. I tried various approches without success, the following does, unsurprisingly not work. FUNCTION accessRTE: BOOL; ****************************** codesyscontrol.stop(); Can you please tell me how I can make a system call to codesyscontrol from a POU. Or could you provide me with a use case for this setting. Many thanks for your feedback and kind regards Andrej
Last updated: 2024-03-02

Post by ofey on EtherCAT fieldbus ^{CODESYS Forge talk (Post)}
Okey, thank you! Do you think it is something in this library, that makes it possible to do the configuration in a PRG? https://content.helpme-codesys.com/en/libs/IODrvEtherCATDriver/Current/IoDrvEtherCAT.html#id1 I think the codesys modbus libraries support configuration and connection to modbus slaves without having to add the slave devices in the device tree. Just do it from function blocks inside the program. I was hoping for something similar with EtherCAT.
Last updated: 2024-04-10

Post by gseidel on CNC - system goes to X=0 Y=0 before CNC file execution starts, how to avoid that? ^{CODESYS Forge talk (Post)}
Hi peterned, the start position given in the CNC properties is only used if you use the compile mode OutQueue. With compile mode SMC_CNC_REF, you need to provide the start position in the IEC application. The function block SMC_NCInterpreter has an input piStartPosition. You can initialize it with the output of the forward kinematic transormation FB for your machine. In your case probably SMC_TRAFOF_Gantry2. Best regards, Georg
Last updated: 2024-04-30

Post by corriibme on Setting array values with JSON Utilities SL ^{CODESYS Forge talk (Post)}
It turns out that you can build JSON structures without ever calling the JSONBuilder function block directly. Instead, create a pointer to JSON.JSONData and invoke the necessary methods on its dereference. The parent object has a parent index of -1 (and an index of 0). EVERY other item (including keys, values, empty arrays and sub-objects) created by the setX methods needs the index to increase by 1. Then use the JSONByteArrayWriter FB to generate your JSON string
Last updated: 2024-05-23

Post by plunje on Sensor not set ^{CODESYS Forge talk (Post)}
A got a larger project but this very small example makes it clear. I have a button, and after it's clicked a lamp should flip on and stays on, and when the mouse-button is released it should stay on. When I try that in the PLC_PRG it works, but when I change it to a function block (seet attched demo proj) it isn't. I'm fairly new to PLC programming but are very experienced C# engineer, but this goes above my head...
Last updated: 2024-05-26

Post by swe-hob on call of a method of a function block in another program ^{CODESYS Forge talk (Post)}
Hi, Let's assume following: PRG_1 fb_1 : fbExample1; fb_1.method_1 do something... PRG_2 fb_2 : fbExample2; fb_2.method_2 if xTest then PRG_1.fb_1.method_1(); end_if; Is there a reason why runtime hangs when I call the method_1 in PRG_1 from a method in PRG_2? Both programs run in the same task. No chance that any other program calls the method. What I practically do there is that in the program PRG_2 I add a structed object into a buffer. In PRG_1 I just process the items in the buffer.
Last updated: 2024-06-03

Post by swe-hob on call of a method of a function block in another program ^{CODESYS Forge talk (Post)}
Hi, Let's assume following: PRG_1 fb_1 : fbExample1; fb_1.method_1 do something... PRG_2 fb_2 : fbExample2; fb_2.method_2 if xTest then PRG_1.fb_1.method_1(); end_if; Is there a reason why runtime hangs when I call the method_1 in PRG_1 from a method in PRG_2? Both programs run in the same task. No chance that any other program calls the method. What I practically do there is that in the program PRG_2 I add a structed object into a buffer. In PRG_1 I just process the items in the buffer.
Last updated: 2024-06-03

Post by joep on Custom robotics kinematics model debugging ^{CODESYS Forge talk (Post)}
When trying to move my axis using any group move instruction I get the following error: SMC_CP_INVALID_PATH_ELEM and axisgroup goes into errorstop state. I tested my methods thoroughly which makes it hard for me to debug. Are there some hidden rules I need to abide to? How would one go about debugging a custom robotics model, since the information inside isn't accesible. Is it possible to find the source of where the function breaks? Any hint in the right direction would be appreciated. Best regards
Last updated: 2024-06-08

Post by timvh on OSCAT Scale_r function not working in LD 4.60 works in LAD2 on 3.5.21sp3 ^{CODESYS Forge talk (Post)}
It seems like a bug in FBD. Work-around: If you click on the small line between the box and the output variable and delete this, the variable is removed. When you then assign a variable again (Ctrl-A), then you will see that the line will be a bit longer. If you then select the previous variable, you will see that it works.
Last updated: 2025-10-26

Post by youness on CSVReaderInit returns error : INVALID_HANDLE ^{CODESYS Forge talk (Post)}
I have Already the same problem when i'm trying to write data more than 10 times in the same file. In fact, i send my data periodicaly to a file that i configured to have permission of W/R in my CodesysContol.cfg. When the Error occurs, i must reboot my machine to success. It means that the problem isn't realted to a limitation of size, but a problem in the function supposed to handle the file. totorovic : allow me to know if you've found a solution to your problem. Thanks.
Last updated: 2025-11-26

Post by nxbp on About Compatibility ^{CODESYS Forge talk (Post)}
Let's say I have a CODESYS controller (PLC) with a runtime version around 3.5.19. If I use development software version 3.5.21.40 or a later version that will be released in the future for programming, could there be any problems or malfunctions in the controller's program execution or in the execution of the new, updated function blocks from the newer software? I mostly work with servo-based motion applications, so please keep that in mind when answering, and provide a detailed answer so I don't have to email you again about this topic.
Last updated: 1 day ago

Post by durallymax on VAR_INFO from inside of a FB to get info on the instance. ^{CODESYS Forge talk (Post)}
The help link appears to be broken. When I implemented something similar I had to add {attribute 'reflection} above the declaration of the FB with {attribute 'instance-path'} above the string VAR that would contain the path. Then wrote a function to trim off however much I wanted removed by searching for periods, then formatting it with spaces at the periods and removing brackets on arrays while also breaking up the PascalCase to present it a bit nicer for the end-users.
Last updated: 10 hours ago

Post by antonz on OSCAT Scale_r function not working in LD 4.60 works in LAD2 on 3.5.21sp3 ^{CODESYS Forge talk (Post)}
That's what I found as well Shaun. I have seen it at least in versions 3.5.21.1 and 3.5.21.3. There seems to be an issue with the FBD/LD package v4.6.0.0. The workaround proposed by Tim works but needs to be done manually on every code change/addition. For now we manually downgrade the FBD/LD package from v4.6.0.0 down to v4.5.0.0 after installation of CoDeSys. Same as you did. I hope this gets fixed on a next patch.
Last updated: 2025-11-21

Post by mondinmr on Frustration-Fueled Feedback on Project File Management and Git Integration ^{CODESYS Forge talk (Post)}
In reality, other vendors are already moving towards integration with VS Code. B&R, for example, is likely the only one that could truly challenge Codesys in the market: they’ve overhauled their once-archaic environment (previously lacking ST OOP) and are now catching up significantly with Automation Studio Code, offering modern programming capabilities and native support for tools like Git and GitHub Copilot. The other big names in the market, frankly, are still light years behind. For smaller projects, typically handled by “wire strippers” (with all due respect!), a classic environment might be just fine. But once you’re dealing with thousands or even millions of lines of code—possibly organized in an OOP paradigm, spanning large teams, integrating third-party libraries, requiring version control, and performing comprehensive tests—a lightweight, responsive editor supercharged with AI-based features becomes essential. The real strength of something like VS Code lies in its vast ecosystem of extensions and integrations: from advanced Git support to automated build/test pipelines, and even AI-assisted autocompletion that already makes software development much more agile and productive. I understand that a PLC project involves more than just ST code (task setup, fieldbus configuration, libraries, etc.). However, there’s no technical reason not to at least provide ST files in a pure text format, making version control and collaboration far easier. B&R has clearly adopted this approach; I hope Codesys will accelerate its own efforts to offer a native, text-based integration and modern development tooling. Once you go beyond a certain level of complexity—dozens of configurations, OOP hierarchies, and distributed teams—you really do need “engineer-level” software tools, not just solutions targeting “wire strippers.” For large-scale automation projects, a more open and flexible approach is the only way to avoid chronic frustration. Let me emphasize that I truly love Codesys and consider the work done so far to be brilliant—I’d be sorry to see it overshadowed by others moving faster in this direction.
Last updated: 2025-02-18

Post by rossanoparis on After un upgrade of "CODESYS Control for Raspberry Pi MC SL" from v4.7 to v4.9 SysFileOpen function stopped working ^{CODESYS Forge talk (Post)}
Hello at all. After un upgrade of "CODESYS Control for Raspberry Pi MC SL" from v4.7 to v4.9 SysFileOpen function stopped working. I'm not able to read or write files from the PLC application. Before this upgrade all worked fine. I've read this thread [ https://forge.codesys.com/forge/talk/Engineering/thread/3da9ded84e/ ] Despite I followed that indications I couldn't get my code working again. Perhaps I'm missing something or I didn't understand how to use placeholders at all. Is there a different syntax to use for "SysFileOpen" in order to use placeholders? Thanks in advance for your help. Information Compiler: CODESYS V3.5 SP19 Patch 2 Runtime: codesyscontrol 4.9.0 HW: KUNBUS RevPi Connect S Below the paths I want to access (The entire CODESYSControl_User.cfg file is attached) [SysFile] PlaceholderFilePath.1=/home/pi/hpca/bin, $hpcabin$ PlaceholderFilePath.2=/home/pi/hpca/cfg, $hpcacfg$ PlaceholderFilePath.3=/home/pi/hpca/logs, $hpcalogs$ PlaceholderFilePath.4=/home/pi/hpca/resources, $hpcares$
Last updated: 2023-08-22

Post by julianramirez on ModbusFB write update ^{CODESYS Forge talk (Post)}
Hello everyone, I am testing the ModbusFB library tcp server and so far I am able to create holding registers successfully, however, I am trying to identify after each write which registers got updated (i.e. function code, write value). I can even see the var udiNumWriteRequests, which increases with every write. I noticed that there is logging with the LogStatusInfo method. After I call it I am able to read in the console stuff that I want. Nevertheless, this is only available at the logs and is not easy to decode because it consists on several messages, I would like to know if there is a way for me to retrieve this information from the function itself with pointers or if there is any way to copy the logs messages (assuming that I can filter them with the LoggingOptions to only show what I need) inside the runtime code and not in the console. Thanks for your help :)
Last updated: 2024-09-16

Post by hyys12 on Help understanding analog in-/outputs ^{CODESYS Forge talk (Post)}
Hello. I am currently working on a WAGO PLC, where I am trying to wrap my head around how the analog inputs and outputs work in codesys. I have looked far and wide on the internet, for a general introduction to the whole concept, but I have not had any luck with finding anything that helped me understand it better. The whole goal is for me to be able to read an analog input from a temperature sensor, as well as using an analog output, to control a frequency inverter. I know these have nothing to do with each other, but that is all I have on hand right now. I am trying to program this using Ladder Diagram. The only thing is, that every video/guide I have seen/read using LD, just adds a whole lot of function blocks, to do all kinds of stuff they don't explain. My general question is, how would one go ahead and read the analog input, as well as transmit an analog output? Is there some kind of specific function block I would have to use for this, or some great video I can watch, to understand the inner workings. Is it somehow possible to see the values the PLC recieved/sends? Regards.
Last updated: 2024-12-11

Post by trusty-squire on Strange problem with the ‘MC_SetPosition’ function ^{CODESYS Forge talk (Post)}
Here, it seems to me that we are getting completely off track with the observed problem. If questions clarifying the details of the installation are problematic, it's best to include those details in the original question then... I had already written this elsewhere. The program before being brought into machines was exhaustively tested in SW emulation and the problem did not occur. Testing the full program in emulation is entirely different from creating a simplified program to isolate the function causing problems in the real world. I would recommend trying it to isolate the issue. The drive and motor have been working fine for about 10 years. In replacing the machine control system, I opted for CoDeSys where before there was something else. But this is not the subject of the problem A simple "yes" is the correct answer to my question here... Anyways, you seem to be a very knowledgeable expert, good luck on your problem!
Last updated: 2025-01-18

Post by atcprojectteam on Modbus Function Code 15, writing multiple coils ^{CODESYS Forge talk (Post)}
Hi all, I am using an RSTI-EP I/O card along with the EPXMBE101 Modbus/TCP network adapter. I have a Control Standard L license. I successfully connected to the I/O card via Modbus and can read inputs without any issues. However, when I try to write to the digital output modules using function code 15, I am unable to make any changes. Here’s what I have done so far: I created a small project using Structured Text. I set up Modbus channels (as shown in the attached image) and mapped the pins. When I use cyclic mode, the connection results in an error. However, when I use the rising edge, the connection works, but I don’t see any changes on the I/O card. For the output module, I assigned one bit to high. After that, I ran CODESYS Control Win V3. (Should I be running the PLC as well?) I built the program, but I am not receiving any response from the I/O card. Could you please advise on what might be causing this issue?
Last updated: 2025-02-26

Post by atcprojectteam on Modbus Function Code 15, writing multiple coils ^{CODESYS Forge talk (Post)}
Hi all, I am using an RSTI-EP I/O card along with the EPXMBE101 Modbus/TCP network adapter. I have a Control Standard L license. I successfully connected to the I/O card via Modbus and can read inputs without any issues. However, when I try to write to the digital output modules using function code 15, I am unable to make any changes. Here’s what I have done so far: I created a small project using Structured Text. I set up Modbus channels (as shown in the attached image) and mapped the pins. When I use cyclic mode, the connection results in an error. However, when I use the rising edge, the connection works, but I don’t see any changes on the I/O card. For the output module, I assigned one bit to high. After that, I ran CODESYS Control Win V3. (Should I be running the PLC as well?) I built the program, but I am not receiving any response from the I/O card. Could you please advise on what might be causing this issue?
Last updated: 2025-02-26

Post by ph0010421 on How to create a stopwatch? ^{CODESYS Forge talk (Post)}
Do you need an 'hours-run' counter? And 1 second resolution is ok? I think you're over-thinking it. (The task time needs to be < 1second) Have a look at the LAD... Then, the time in seconds can be made into hh:mm:ss with this FUNction Declarations: FUNCTION funSecondsToStringTime: string VAR_INPUT InSeconds: UDINT; END_VAR VAR AsString: STRING; Minutes: UDINT; Hours: UDINT; Seconds: UDINT; MinutesAsString: STRING(2); HoursAsString: STRING(2); SecondsAsString: STRING(2); END_VAR and the code: Hours := InSeconds / 60 / 60; //Derive hours Minutes := (InSeconds - (Hours * 60 * 60)) / 60; //Derive minutes Seconds := InSeconds - ((Hours * 60 * 60) + (Minutes * 60));//Derive seconds HoursAsString := UDINT_TO_STRING(Hours); MinutesAsString := UDINT_TO_STRING(Minutes); SecondsAsString := UDINT_TO_STRING(Seconds); IF LEN(HoursAsString) = 1 THEN HoursAsString := CONCAT('0',HoursAsString); END_IF; IF LEN(MinutesAsString) = 1 THEN MinutesAsString := CONCAT('0',MinutesAsString); END_IF; IF LEN(SecondsAsString) = 1 THEN SecondsAsString := CONCAT('0',SecondsAsString); END_IF; AsString := CONCAT(HoursAsString, ':'); //assemble string AsString := CONCAT(AsString,MinutesAsString); AsString := CONCAT(AsString,':'); AsString := CONCAT(AsString, SecondsAsString); funSecondsToStringTime := AsString;
Last updated: 2023-12-08

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