Post by timvh on Using a raspberry pi and NVLs to log variables outside of Codesys ^{CODESYS Forge talk (Post)}
Yes, this will work.
Last updated: 2025-11-21

Post by jbcregen on Accessing parameters from a structure or function block with the web interface ^{CODESYS Forge talk (Post)}
I have a project with hundreds of OPC-UA variables available on the network. A lot of these variables are used actively in various scripts that run in background in the OS (Linux). I'm experimenting with Automation Server and I have a hard time understanding how the web interface populates its parameters list for a given PLC (<plc details="" parameters="" for="" plc="" 'xyz'="">).</plc> In this page, it looks like the only variables available are the ones that are of a "base" type : bool, TIME, String, INT, etc. All the variables that are nested into function blocks or structures are not available in the web interface, even if they are available to any OPC-UA client. Is this a limitation of the Automation Server or is there something that can be done in Codesys?
Last updated: 2025-12-01

Post by baott569 on Limitation on OPC UA Variable 100+ variables on raspberry pi ^{CODESYS Forge talk (Post)}
Sorry, not trying to spam, My internet lagged and I thought the comment wasn’t submitted
Last updated: 2026-01-22

Post by baott569 on Limitation on OPC UA Variable 100+ variables on raspberry pi ^{CODESYS Forge talk (Post)}
Hi, did you manage to resolve this issue?, I’m experiencing the same problem
Last updated: 2026-01-22

Post by hannibal on Codesys Trend - setting Y axis minimum and maximum as variables - error ^{CODESYS Forge talk (Post)}
I am experiencing an issue when trying to define the Y-axis limits in a Trend Graphic using variables. When I set the Minimum and Maximum values as variables, an error is triggered. My goal is to make the Y-axis limits dynamic so they can adjust according to the installation. Both variables are initialized as follows: gP_YMin = -100.0 gP_YMax = 100.0 However, I still get the following error: "The minimum axis value must be less than the maximum axis value" Does anyone have an idea why this is happening or how to resolve it?
Last updated: 2026-03-22

Post by hannibal on Codesys Trend - setting Y axis minimum and maximum as variables - error ^{CODESYS Forge talk (Post)}
I am experiencing an issue when trying to define the Y-axis limits in a Trend Graphic using variables. When I set the Minimum and Maximum values as variables, an error is triggered. My goal is to make the Y-axis limits dynamic so they can adjust according to the installation. Both variables are initialized as follows: gP_YMin = -100.0 gP_YMax = 100.0 However, I still get the following error: "The minimum axis value must be less than the maximum axis value" Does anyone have an idea why this is happening or how to resolve it?
Last updated: 2026-03-22

Post by clarenced on Multiple applications on one device sharing variables. ^{CODESYS Forge talk (Post)}
Sounds feasible, but how would I create this object so that both applications would use the same instance of it. If this did work, it's still not really the solution I am looking for as it would mean mapping every variable I want to use on the hmi through this object vs I was hopping all the GVL variables would be available.
Last updated: 2025-02-20

Post by timvh on IECStringUtils.FormatDateTime ^{CODESYS Forge talk (Post)}
There has been a fix in SP21. I tried it in this version with the option "Use unicodestring" enabled in the Visualization Manager and it worked if the variables used for the function are declared as WSTRING variables wsFormat : WSTRING := "%t[HH:mm:ss dd.MM.yyyy]"; wsTime : WSTRING; IECStringUtils.FormatDateTime(cbpResult := ADR(wsTime), uiResultCapacity := SIZEOF(wsTime), cbpFormat := ADR(wsFormat));
Last updated: 2025-07-29

Post by blitz on Latch alarm variables from the PLC runtime ^{CODESYS Forge talk (Post)}
Hi, I have a question. Does anyone know a way to change latch alarm variables from the PLC runtime? In the help there is a method described: https://content.helpme-codesys.com/en/libs/AlarmManager/Current/Interfaces/pou-IAlarm3/SetLatchVarValue.html but I don’t know how to use it correctly.
Last updated: 2025-09-23

Post by gatto on variables between two applications ^{CODESYS Forge talk (Post)}
No. As you can see in the uploaded image, in my test project, I have a variable list GVL_1 which is located in appication_1. But if I write in POU_2, which is instead found in application 2, I cannot find the variables of GVL_1. it seems that the GVLs are children of each app
Last updated: 2024-06-24

Post by noah on "Invalid Value" for Variables at Runtime ^{CODESYS Forge talk (Post)}
Hello, I also have the problem that suddenly all variables in my project were invalid and shown as "???" during runtime. Could you manage to fix the problem in the last 4,5 years ;) ? Because I tried everythin to fix it but nothing worked. I feel like maybe this is a bug. Thank you.
Last updated: 2026-03-09

Post by noah on "Invalid Value" for Variables at Runtime ^{CODESYS Forge talk (Post)}
Hello, I also have the problem that suddenly all variables in my project were invalid and shown as "???" during runtime. Could you manage to fix the problem in the last 4,5 years ;) ? Because I tried everythin to fix it but nothing worked. I feel like maybe this is a bug. Thank you.
Last updated: 2026-03-09

Post by davidmic on Struct Literal ^{CODESYS Forge talk (Post)}
Hi all I want to pass a struct into a function without declaring the struct in a VAR/END_VAR. Is this possible? I think this would be called a struct literal It would look something like this someFB.write(structArgument := MyStruct#(a := 1, b := 1.2), otherArgument := TRUE); With this struct declaration TYPE MyStruct : STRUCT a : INT; b : REAL; END_STRUCT END_TYPE
Last updated: 2025-03-28

Post by davemansell on explicit cast ENUM to UINT and vice versa ^{CODESYS Forge talk (Post)}
This is from sometime ago but below might help someone else; this could be done via POINTERS. Make sure you protect for NULL pointers etc if you take this approach. // DECLARATION myEnumValue : enumMyEnum; u8 : USINT; pmyEnumValue : POINTER TO enumMyEnum; pu8 : POINTER TO USINT; // CODE pu8 := ADR(u8); pmyEnumValue := pu8; myEnumValue := pmyEnumValue^; // dereference the pointer
Last updated: 2025-08-21

Post by davemansell on explicit cast ENUM to UINT and vice versa ^{CODESYS Forge talk (Post)}
This is from sometime ago but below might help you could do this via POINTERS. Make sure you protect for NULL pointers etc if you take this approach. // DECLARATION myEnumValue : enumMyEnum; u8 : USINT; pmyEnumValue : POINTER TO enumMyEnum; pu8 : POINTER TO USINT; // CODE pmyEnumValue := pu8; myEnumValue := pmyEnumValue^; // dereference the pointer
Last updated: 2025-08-21

Post by rajesh008 on i can't declear the address in GVL - codesys SP19 Patch5 ^{CODESYS Forge talk (Post)}
The “_AB AT %IW0:word; ” if i called the value then im getting this error. like below "the declartion of the variable with an address assignment cannot be used in a PRG or GVL with the attribute 'subsequent'" This is happening when the GVL is selected in Redundancy Configuration. if i un-select the address declaration is working fine
Last updated: 2024-05-13

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 ulvis on CFC Pages Cut&Paste is not working at its best ^{CODESYS Forge talk (Post)}
In the CFC page oriendted editor, if I copy some elements consisting of an input connector, some connected logic and an output connector and then paste this on a another page then the pasted elements get inserted with an offset to the right so that the rightmost connector falls outside of the page, in the grey hatched area. So far so good. Then I mark all the elements and try to drag them into the correct placement, collectively. THIS IS NOT POSSIBLE! I only get the "forbidden" icon tooltip. One has to drag & drop the INDIVIDUAL elements to move the elements around. What am I doing wrong?
Last updated: 2025-05-15

Post by ulvis on CFC Pages Cut&Paste is not working at its best ^{CODESYS Forge talk (Post)}
In the CFC page oriendted editor, if I copy some elements consisting of an input connector, some connected logic and an output connector and then paste this on a another page then the pasted elements get inserted with an offset to the right so that the rightmost connector falls outside of the page, in the grey hatched area. So far so good. Then I mark all the elements and try to drag them into the correct placement, collectively. THIS IS NOT POSSIBLE! I only get the "forbidden" icon tooltip. One has to drag & drop the INDIVIDUAL elements to move the elements around. What am I doing wrong?
Last updated: 2025-05-15

Post by ulvis on CFC Pages Cut&Paste is not working at its best ^{CODESYS Forge talk (Post)}
In the CFC page oriendted editor, if I copy some elements consisting of an input connector, some connected logic and an output connector and then paste this on a another page then the pasted elements get inserted with an offset to the right so that the rightmost connector falls outside of the page, in the grey hatched area. So far so good. Then I mark all the elements and try to drag them into the correct placement, collectively. THIS IS NOT POSSIBLE! I only get the "forbidden" icon tooltip. One has to drag & drop the INDIVIDUAL elements to move the elements around. What am I doing wrong?
Last updated: 2025-05-15

Post by ulvis on CFC Cut & Paste not working at its best. ^{CODESYS Forge talk (Post)}
In the CFC page oriendted editor, if I copy some elements consisting of an input connector, some connected logic and an output connector and then paste this on a another page then the pasted elements get inserted with an offset to the right so that the rightmost connector falls outside of the page, in the grey hatched area. So far so good. Then I mark all the elements and try to drag them into the correct placement, collectively. THIS IS NOT POSSIBLE! I only get the "forbidden" icon tooltip. One has to drag & drop the INDIVIDUAL elements to move the elements around. What am I doing wrong?
Last updated: 2025-05-15

Post by danieldiaz on Problem with FB execution ^{CODESYS Forge talk (Post)}
Hello everyone, I've been working on a system which needs an error function, with this purpose I've created a FB programmed in LD, after debugging I run the simulation. It seems that the variable linked to a coil doesn't change the value when the contacts are associated to input variables. When I use internal variables the logic works properly. I don't know if the problem is related to the variables definition or with the logic program. As you can see in the image, I1 and I2 are variables declared on the FB, the rest are input variables. If I force the eStop and Reset signals to TRUE the coil value should change, but it doesn't. However in the second network if I1 is TRUE the coil change to TRUE as it has to be. To sum up, my doubt is why that coil doesn't change its value? I would like someone to shed a light on this. Thanks!
Last updated: 2024-04-02

Post by fedex03 on Read Global Variable from an IoT Device ^{CODESYS Forge talk (Post)}
Hello everyone, I am new to the forum, and to programming with CodeSys. I am dealing with IoT device for industry and I should check if a device is able to read/write global variables in an EtherNet/IP Master. Since I do not have an EtherNet/IP PLC, I thought of using CodeSys as a softPLC. I created a program with a set of global variables (GVL) and a task that increments them. I would like to know if I need to enable any options so that the global variables can be read by IoT devices. My device supports Class 2 Class (Explicit Messaging Connection) communication. Thank you in advance for your help.
Last updated: 2025-07-22

Post by timvh on Codesys 3.5.18.60 – Application Loss and Persistent Data Corruption ^{CODESYS Forge talk (Post)}
Which device do you use? Does this have persistent memory (e.g. NVRAM) available? Maybe first ask your PLC vendor about the possibilities and how they advice to use persistent variables? If you have no NVRAM available, CODESYS will store the variables in a file when the device gracefully shuts down. But on an abrupt power failure, this is not possible. If you have no NVRAM and you want to use persistent variables, then consider using a UPS. In this case when the power is lost, the UPS can keep the power on the PLC which then can gracefully shut down. Alternatively use the Persistence Manager to store the variable values in a file e.g. only on change. See: https://content.helpme-codesys.com/en/CODESYS%20Application%20Composer/ac_pm_overview.html
Last updated: 2025-08-26

Post by durallymax on Persistent Vars ^{CODESYS Forge talk (Post)}
Looking for a better way to manage Persistent Variables. We tend to have local vars in our FBs that need persistence through downloads as the systems are updated/altered on a regular basis. Retain would suffice if we had an easy mechanism to backup and restore like we can with Persistent variables and recipes. Although not having to remember that step with Persistent variables is preferred. We're running into issues with persistent storage capacity (WAGO PFC200) using the Persistent variable list (and adding all instances). It appears there are many ways to handle this, some with recipes, some with files, others with application manager. Is there a solution that exists that is as simple as declaring as Persistent and managing elsewhere? Or do we need to move onto periodically writing CSVs?
Last updated: 2025-09-22

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