Post by squiggleypuff on RemoteTargetVisu creates Unresolved Reference ^{CODESYS Forge talk (Post)}
I have a project with a Festo CPX-E-CEC-C1-PN PLC (Run-time version 3.5.12.50) that I have been developing on just fine using Codesys V3.5 SP19 Patch 5 (64bit). I am at the stage where I wanted to use the Festo HMI screen, and have added a RemoteTargetVisu object to my application. After adding this object, I am no longer able to log in to the PLC as I get an Unresolved Reference warning for 'USERMGRUSERGETPROPERTY' towards the end of the download process. I was able to find this post (https://forge.codesys.com/forge/talk/Visualization/thread/fc686a6cb2/) where the two possible solutions are to "set the placeholder to emtpy" or update the runtime. Problem is, I don't know how to do either of these things, as I'm still very green in Codesys land. I'd be happy to update the Festo PLC runtime, as that seems like the better option, but have not had any luck in finding a tutorial for this online. If anyone could point me in the right direction I'd appreciate it.
Last updated: 2024-03-19

Post by william-blandon on RecipeManCommands.ReloadRecipes ^{CODESYS Forge talk (Post)}
Hi Dave. Thanks for your answer. I still struggling with this. I have done everything according with the Codesys help even I have looked in detail at the example. I have double checked the recipe manager configuration and the use of all the methods. There are two methods that do not work as expected. I'm using Codesys 3.5.19.20 and recipe management 4.4.0.0 .CreateRecipe just create a recipe in the recipe definition but do not create the file. This have a walk around just giving a .ReadAndSaveRecipe afterwards. .ReloadRecipes do nothing but do not generate any error as well. After calling it I call the .GetRecipeCount and the number is always 0. When I create a new recipe (using the function block methods) then the number changes. Looks like this method is looking to the wrong directory finding nothing. I don't know if there is a missing configuration in the CODESYSControl.cfg file. I'm thinking in a walk around for this but I need to create a strings array with the recipe names as retentive and making all the management when deleting and adding recipes. Have had some one the same problem?
Last updated: 2024-05-23

Post by shamcke on Array with generic constant as persistent variable ^{CODESYS Forge talk (Post)}
Hello, I have written a function block that uses a generic constant for the upper bound of an array. I wanted to have this array in the persistent memory area, thus I constructed my FB as follows: FUNCTION_BLOCK FbWithGenericArrayLength VAR_GENERIC CONSTANT uiArrayLength : UINT := 10; END_VAR VAR PERSISTENT arr : ARRAY[1..uiArrayLength] OF INT; END_VAR In my PLC_PRG I declare an instance of said FB PROGRAM PLC_PRG VAR myFb : FbWithGenericArrayLength<10>; END_VAR This compiles just fine. When I let CODESYS fill my persistent list, it adds duplicate entries {attribute 'qualified_only'} VAR_GLOBAL PERSISTENT RETAIN // Generated instance path of persistent variable PLC_PRG.myFb.arr: ARRAY [1..uiArrayLength] OF INT; // Generated instance path of persistent variable PLC_PRG.myFb.arr: ARRAY [1..uiArrayLength] OF INT; END_VAR so I manually delete the duplicate. When i now compile, I get errors ------ Build started: Application: Device.Sim.Device.Application ------- Typify code... [ERROR] Sandbox_FW31: PersistentVars [Device: PLC Logic: Application](Line 4): C0161: Border 'uiArrayLength' of array is no constant value [ERROR] Sandbox_FW31: PersistentVars [Device: PLC Logic: Application](Line 4): Type of mapped variable is not equal to original type Compile complete -- 2 errors, 0 warnings Build complete -- 2 errors, 0 warnings : No download possible Is is simply not possible to use a generic constant for the persistent array? Thanks in advance. Edit: It seems I can manually replace the uiArrayLength in the persisten list by the value 10 I used as the generic constant for this particular instance.
Last updated: 2026-05-29

Post by danp1406 on Question about Demo License limitations for Modbus TCP communication and Fieldbus Instances ^{CODESYS Forge talk (Post)}
Hello everyone, I am currently working with CODESYS Virtual Control for Linux running in Docker on a Debian virtual machine. I am deploying my application using Deploy Control SL, and in my project I am using the ModbusFB library to implement Modbus TCP communication. My setup is the following: I am trying to establish a Modbus TCP connection between a virtual PLC (CODESYS acting as Modbus TCP Client/Master) and a Siemens S7-1200 PLC acting as a Modbus TCP Server. From the Debian VM, I can successfully ping the S7-1200 and verify that port 502 is open using tools like nc. Network-wise, everything appears to be correct. However, when running the application in CODESYS, I receive messages such as “Demo mode for Modbus/TCP Master started. Will expire and stop!” and socket errors like “ClientSocket.UpdateStatus socket error 111 disconnecting.” The ClientTCP block from the ModbusFB library attempts to connect, but the connection does not remain stable. My main question is whether the CODESYS demo license explicitly limits or interrupts Modbus TCP Master communication. Is it expected that in demo mode the runtime will automatically close sockets after some time or prevent stable Modbus TCP connections? I would like to confirm whether this behavior is normal when using ModbusFB in demo mode, or if I should continue troubleshooting the configuration. Additionally, I would like clarification regarding the “fieldbus instances” mentioned in CODESYS licensing options (for example, 2, 4, or 16 instances). What exactly is considered one fieldbus instance? Does one Modbus TCP Client block count as one instance? Does each active connection to a different device count separately? Do Modbus TCP Master and Server count independently toward the total number of instances? Finally, I would appreciate clarification on any other practical limitations of demo mode when using industrial communication libraries such as ModbusFB. Are there limits on the number of connections, number of requests, or communication duration? I am trying to determine whether demo mode is sufficient for testing a virtual PLC communicating with a Siemens S7-1200 over Modbus TCP, or whether a full license is required even for this kind of validation scenario. Thank you in advance for any guidance.
Last updated: 2026-02-25

Post by brouwyka on JSONByteArrayWriter string result incorrect order ^{CODESYS Forge talk (Post)}
Hi @TimvH, As discussed in our email contact, your example does not actually test/reproduce the bug I am describing: Adding to the JSON builder on later cycles works fine. Your example works because you do the following: 1. You finish the first cycle (xFirst) with adding an object to the array with 2 fields; 2. When the next cycle is triggered (xAdd), you immediately start with adding another object to that array. This works fine as the last thing you did before #2 was the addition of the array and an object to it. To reproduce the bug you should be doing the following instead, as I showed with the code I shared with my first post: 1. Create the array - save the index that is returned; 2. Add an item, either a primitive or an object, to the array; 3. Add an item outside the array (anything: a primitive, a new array, a nested object, etc); 4. Add another item to the array using the index you saved at #1. You will now see, as I shared in my initial post, that the second item is placed completely outside the root JSON object. This also happens to anything else you try to add after step #4: everything after this point will be added outside the root JSON object: the JSON is completely broken. Important to note is that this not only happens with arrays, but also with nested JSON objects. Once you add something outside of a nested JSON object, you can no longer add anything to that nested JSON object, as that causes the exact same bug. This also applies to arrays of objects, so if in your test you had tried adding a new key-value pair to the first nested object in your array after you created the second nested object, you would also run into this bug. It seems that the JSONByteArrayWriter (I haven't tested the other writers in the JSON Utilities SL library, so I don't know if they suffer from the same problem) simply does not handle any JSON fields that add brackets (so arrays with "[" & "]" and nested objects with "{" & "}") well, and closes them prematurely instead of checking if any later JSONElements in the JSONData's array belong to any of these bracketed fields. After reviewing the objects & functions of the JSON Utilities SL library, my guess is that either the JSONByteArrayWriter linearly goes through the array of JSONElements in the JSONData and only checks the diParentIndex of each JSONElement in direct ascending order, OR if it does use the JSONElement.GetChildren(); method, that this method is either broken and doesn't give all children correctly to the writer. Neither explains why everything completely breaks, and you cannot even add to the root JSON object anymore, however, so there is probably more than just that going wrong in the writer. To me, after a full week of testing and attempting workarounds, this seems like a bug in the library that needs to be fixed by Codesys, as I cannot see anything wrong in the JSONData constructed by the JSONBuilder - this seems purely a problem in the writer.
Last updated: 2026-06-15

Post by rossanoparis on How to configure CODESYSControl_User.cfg in order to use a specific network card for OPCUA Server ^{CODESYS Forge talk (Post)}
Hello at all I'd like to know how to configure CODESYSControl_User.cfg in order to use a specific network card for OPCUA Server. In the past, I tried to ask in "Forge" about this topic, but I could find neither help nor document informations about it. Reading the file "codesyscontrol.log" I see these logs OPC UA Server Started: Hostname: NTLRPICTRL01, Port: 4840 URL: opc.tcp://NTLRPICTRL01:4840 Loopbackadapter activated. **All available networkadapters are used.** Multithreading activated. 3 workers used. My controller, which is a Linux PC, has got two network cards eth0 and eth1 I whant to use the card with name "eth0" as a server for OPCUA and keep the "eth1" free for other stuffs. Is it possible ? Best regards Rossano
Last updated: 2023-08-25

Post by sangeetnenwani on Test Driver Availability in CODESYS 64-bit and Test Manager 5.1.0.0 ^{CODESYS Forge talk (Post)}
I’m operating with CODESYS in a 64-bit configuration and the Test Manager at version 5.1.0.0, where I’m attempting to use project scripts from an earlier version. These scripts call for certain test drivers that are not present in my installation. It’s unclear whether the absence is due to the 64-bit system, an update in the test drivers, or if I need to enable or install additional elements. For instance, the loadproject(Codesys.Base) command is missing, but loadproject(testmanager.project) is available. The FileIO command for CODESYS isn’t accessible, yet the testmanager’s driver for it exists, as does the execuptscript command.
Last updated: 2024-08-06

Post by sangeetnenwani on Test Driver Availability in CODESYS 64-bit and Test Manager 5.1.0.0 ^{CODESYS Forge talk (Post)}
I’m operating with CODESYS in a 64-bit configuration and the Test Manager at version 5.1.0.0, where I’m attempting to use project scripts from an earlier version. These scripts call for certain test drivers that are not present in my installation. It’s unclear whether the absence is due to the 64-bit system, an update in the test drivers, or if I need to enable or install additional elements. For instance, the loadproject(Codesys.Base) command is missing, but loadproject(testmanager.project) is available. The FileIO command for CODESYS isn’t accessible, yet the testmanager’s driver for it exists, as does the execuptscript command.
Last updated: 2024-08-06

Post by jacobwago on v3.5 SP19 - Modbus TCP Devices - Channel Limit? ^{CODESYS Forge talk (Post)}
Hello, I have experienced the same issue as described above but for the Modbus Serial configurator. Looking for a solution. In v3.5 SP19 Patch 7 the Modbus Serial Master Slave configurator has a "virtual" limit of 10 channels. In v3.5 SP18 Patch 5 this virtual limit does not exist. I can successfully copy back and forth from 18 to 19 with out any build error. However, this is not a good solution for our customers. What is even more confusing is that the IoDrvModbus library is the same version (4.3.0.0) for both SP18 and SP19. Please help in providing a fix to the virtual channel limit of 10 in SP19. Thanks,
Last updated: 2024-09-29

Post by arcadium on Library ENUM text representation in visualization ^{CODESYS Forge talk (Post)}
Hello, Maybe someone could help with this. When I add ENUM to a text field I get the number instead of the text. For my own ENUM variable I have declared and enabled text list value is displayed as text, but I need enum text displayed from softMotion and other internal FB's. In the picture I have one of desired ENUM variable setup, but in the visu I have number, but in the watch window it's text. There is probably some checkbox to tick, but was looking for an hour, can't find a solution. Would apreciate some help
Last updated: 2024-12-24

Post by arcadium on Library ENUM text representation in visualization ^{CODESYS Forge talk (Post)}
Hello, Maybe someone could help with this. When I add ENUM to a text field I get the number instead of the text. For my own ENUM variable I have declared and enabled text list value is displayed as text, but I need enum text displayed from softMotion and other internal FB's. In the picture I have one of desired ENUM variable setup, but in the visu I have number, but in the watch window it's text. There is probably some checkbox to tick, but was looking for an hour, can't find a solution. Would apreciate some help
Last updated: 2024-12-24

Post by kut69 on Retain / Persistent Variables in Codesys for Raspberry Pi ^{CODESYS Forge talk (Post)}
Hi, I am interested in details about the .ret file in the filesystem. I have already a project where the file is used (write on demand, read by start) and I want to share it as 'default input' for test devices using the identical application. Opening the .ret file content in a hex editor (I only use a single string retain var) I asked myself what the meaning of the first 24 bytes is. It neither contains a handle to the application nor a reference to the variable. Is this maybe a timestamp? Or a CRC/checksum? Regards, Thomas
Last updated: 2025-05-19

Post by imuser on Is it possible to use debug functions such as Step Execution while the PLC ladder is in Running? ^{CODESYS Forge talk (Post)}
Hello, I am a student learning CODSIS. Lately, I've been curious about something. During the actual PLC run, that is, Assume that the I/O is connected to a physical device and the analog value is updated in real time. Is it possible to use a feature like Codesys’ Debug-Step Over-Step IN? If possible..... How do I process the values of analog values (pressure sensor, temperature, current, etc.) that are being updated in real time? To step over, the ladder must stop at the breakpoint. If that happens, the PLC will actually stop, right??
Last updated: 2024-01-16

Post by mp9876 on Attempting customizing menus fails in LADDER environment; due to free CODESYS version ? ^{CODESYS Forge talk (Post)}
Hello, I am attempting to get started here and bumping into this funny issue. I am using this version of CODESYS: ============================== DETAILED VERSION INFORMATION Created at 2024-03-10 ============================== Startup profile: ............................................................... CODESYS V3.5 SP19 Patch 6 OS version: .................................................................... Microsoft Windows NT 10.0.19045.0 .NET version: .................................................................. 4.0.30319.42000 When attempting to customize the menus or toolbar it does not work. The additional commands, Insert TON box & Insert TOFF box, are present in the Customize Menus or Toolbars when re-opening the Customize options but neither the menu or the toolbar gets updated with these. Would also like to add them in the Ladder Toolbox as there are only 9 items in there which does not include the one mentioned above. Due because of the version I am using ? Any assistance would definitely be appreciated. Thank you Mike
Last updated: 2024-03-10

Post by vernon-laurence on EtherCAT fieldbus ^{CODESYS Forge talk (Post)}
The simplest way to do this would be to add a bus coupler dedicated to the expansion IO. The EtherCAT network does not fault when modules connected to the expander are not present. In the image below, nothing below the red line is present in the network - with the network working correctly. In your "base" project, simply include all of the possible modules, and then plug them in as you add pumps to the system. I would also highly recommend against the use of direct addressing. There are other methods to accomplish this, including using the "Optional" checkbox for modules and explicitly addressing them. Although, this would require more upfront work to design the network, and some additional work each time modules were added. https://content.helpme-codesys.com/en/CODESYS%20EtherCAT/_ecat_edt_slave_slave.html
Last updated: 2024-04-09

Post by jasperclauwaert on Persistent Retain Variables Not Visible in Online View (WAGO PFC100 + CODESYS) ^{CODESYS Forge talk (Post)}
Hi everyone, I’m working on a WAGO PFC100 with CODESYS. During development everything worked fine, but in the final stage I set several variables to PERSISTENT RETAIN. When I go online, most of these persistent variables cannot be monitored. Instead, I see: <Value of the expression cannot be retrieved> Interestingly, a few variables do show their values correctly, but the majority do not. The variables are not used as pointers or in any unusual way. The application compiles and runs without errors. Has anyone experienced this before? Is this a known issue with PFC100 or CODESYS? Any ideas on what could cause this behavior? Thanks in advance! Jasper
Last updated: 2025-10-23

Post by jasperclauwaert on Persistent Retain Variables Not Visible in Online View (WAGO PFC100 + CODESYS) ^{CODESYS Forge talk (Post)}
Hi everyone, I’m working on a WAGO PFC100 with CODESYS. During development everything worked fine, but in the final stage I set several variables to PERSISTENT RETAIN. When I go online, most of these persistent variables cannot be monitored. Instead, I see: <Value of the expression cannot be retrieved> Interestingly, a few variables do show their values correctly, but the majority do not. The variables are not used as pointers or in any unusual way. The application compiles and runs without errors. Has anyone experienced this before? Is this a known issue with PFC100 or CODESYS? Any ideas on what could cause this behavior? Thanks in advance! Jasper
Last updated: 2025-10-23

Post by gseidel on Mismatch between coordinate monitor and actual motion using SMC_GroupJog2, MC_MoveLinearAbsolute (6DOF) ^{CODESYS Forge talk (Post)}
Hi darwin03, as can bee seen at the end of your video, the direction of rotation now seems correct for all axes. I can only guess, but the most likely reason are different denavit hartenberg parameters in the SoftMotion axis group editors and the robot used in the simulation tool. Maybe some arm lengths differ, maybe some offsets are given with opposite sign. I would again refer you to https://content.helpme-codesys.com/en/libs/SM3_Transformation/Current/SM3_Transformation/Function-Blocks/Standalone-Kinematics/Articulated-Robots/6AxisArticulated/Kin_ArticulatedRobot_6DOF.html. Please double check all parameters and the table of the DH parameters given there and compare that against the robot in the simulation tool. Also: did you configure any tool in CODESYS? I would suggest to simplify and remove any tools for finding the source of the wrong movements. Best regards, Georg
Last updated: 2026-10-16

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 mubeta on Strange problem with the ‘MC_SetPosition’ function ^{CODESYS Forge talk (Post)}
Hi gseidel, before moving to HW implementation, I had created the same program in simulation mode with virtual drives and, as far as I remember, everything worked fine simulating process and the few useful inputs. So it does not seem to be a SoftMotion library problem, but rather a problem with dynamics or physical axis adjustments. What escapes me, however, is the fact that this function is supposed to perform a position shift virtually, in fact without interfering with the axis itself, thus independent of its adjustments. MC_SetPosition() is not a homing function, in fact it is clearly intended to be executed on the fly with the axis moving. Now I'll see if I can reduce the program, although I don't like it very much. In my life I have learned that problem searches should be done on the part, and not in a more or less similar way.
Last updated: 2025-01-10

Post by willbechel on Errors about PLC configuration in CoDeSYs software ^{CODESYS Forge talk (Post)}
I saved it as the same project but in a different location. I opened this "new project". I clicked on the "Direct Login from Automation Builder" button. It automatically directed me to CODESYS, where I was able to create the "Create Boot Project" but first I also clicked login again but inside CODESYS keeping the automation builder login online. Additional Information: The "Create Boot Project" function in CODESYS is used to create a project that will automatically start when the controller is booted up. To create a boot project, you must first create a new project in CODESYS. Once you have created a new project, you can then use the "Create Boot Project" function to create a boot application. The "Create Boot Project" function will create a new application that is based on the current project. The new application will be saved in the same location as the current project. You can then download the new application to the controller.
Last updated: 2024-02-01

Post by mondinmr on Direct Pointers in IOMapping for EtherCAT with IoDrvEthercatLib.ETCSlave_Dia ^{CODESYS Forge talk (Post)}
Using SDO, I can read the EtherCAT mappings and offsets from various registers like 0x1c12, 0x1c13, etc. When I obtain registers mapped in the PDOs and various offsets, I could technically access directly to the statusword, controlword, etc., if they are mapped. I have noticed that on IoDrvEthercatLib.ETCSlave_Diag I can find pointers to the input and output buffers. However, although the input buffer can be easily read by referring to what has been obtained from the SDOs, it is not possible to write to the output buffer, as it is overwritten in each cycle by the data from the IOMapping task. Is there a way, knowing an instance of IoDrvEthercatLib.ETCSlave_Diag, to obtain the pointer to the first data in the IOMapping? The offsets are identical to those of the PDOs, but obviously the data is a copy. For me, the cleanest thing would be to access the pointers on IOMapping, for DS402a devices to retrieve the key data and point them to internal references. I need to know this as, having developed our own motion library, I would like to simplify the initial setup by eliminating unnecessary and nonsensical mappings that can lead users to unnecessary errors. In the current version that we have been using for years, we have to map everything manually. I would like to pass only the slave reference to the FB_init constructors and eliminate the mapping.
Last updated: 2024-02-12

Post by acc00 on Main Task cycle too long leading to PLC Fail ^{CODESYS Forge talk (Post)}
I have 2 Wago PFC200 PLC, running with Runtime SP19 Patch 5, with the Redundant application. The PLC communicates as Modbus Master with at this moment 15 Modbus Slaves -later there will be 28 in total- (Drives, Power management units,...). These devices are connected in 2 rings (1 ring of Drives, 1 ring of Power Management units), with 2 Managed Moxa Switches being part of the ring. Each PLC is connected to one of these switches. The issue I'm encountering is that the Cycle time of the Active PLC goes very high when I'm closing the Drive ring (simulating an issue on one Cabinet supply, resulting in that one Drive shut down, which can happen on field quite often). As a result of this long cycle, the PLC fails and goes to Exception, and the Passive PLC does not take control of the system. A normal cycle is around 30ms for the Main task, and a few ms for the Ethercat task. When I monitor with Profiler, I see that in this Maximum Cycle, the main Task is only taking 13ms, so I'm not sure where the PLC is hanging for so long. Is the remaining cycle time the Redundant management/sync or something else? Thank you in advance.
Last updated: 2024-03-08

Post by rabaggett on Reading Named Pipes in Linux Is there a better way? ^{CODESYS Forge talk (Post)}
I have a Python program that will handle things in my application such as VISA over IP and Telnet control of instruments. I want the main control and HMI in Codesys. My problem is communication between the two. I have looked at several ways to accomplish this, and settled on having the Python program create two named pipes, one to send information to Codesys, and one for Codesys to send information to Python. The information would be packetized with \n for end of packet.. Seems simple. I think the named pipes method should work, but file reading in Codesys using the CAA file library starts to get difficult when the file is never ending, as in this case. Before I spend too much time making something that may be fundamentally flawed I want to ask. Is there a better way? Is there a way to read the file 'one line at a time' which might solve my never ending file problem? Thanks!
Last updated: 2024-05-09

Post by lukasz on Unresolved reference when trying to upload to Codesys Runtime V3 ^{CODESYS Forge talk (Post)}
Hello! I'm working with Codesys SP21 Patch 4. The project builds without any errors. When trying to upload my project to Codesys Runtime V3 x64 I get a lot of Unresolved Reference errors, all with FU- at the start and then -CLOSELAYER2, -GETBUSINFO, -GETFRAME etc. I also get a error pop-up that I should 'update device' in the project but it's not specified to which version or anything useful really.There's also not much to choose from. When I check Runtime version in the systray I get 3.5.21.40 and it's the same as I have set up in the project as the device. All information I get is that it should be clear from the errors but no useful information is provided in the errors. Do I need to install some library? I checked other posts and for different reference error and this was the answer. Thanks in advance!
Last updated: 2026-03-25

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