Post by brouwyka on JSONByteArrayWriter string result incorrect order ^{CODESYS Forge talk (Post)}
Hello everybody! We are currently working on implementing a call to an API that tracks data sent to it through a JSON body. Versions: CODESYS V3.5 SP19 Patch 7 using IIOT Libraries SL license, specifically JSON Utilities SL version 1.13.0.0. For simplicity, let's say we want to construct the following JSON body for our request (simplified to just 1 key-value pair in each of the array objects to keep things shorter, but we'd have multiple fields in each in reality): { "id": "machine_1", "readings": [ { "temp_mid": 153.8 }, { "temp_mid": 98.3 } ], "status": "RUNNING" } However, our "readings" data is added over time, not in creation, so calls to the builder would be somewhat out of order. In a simplified manner, our calls would look like this: jsonBuilder(pJsonData := JsonData, diRootObj => rootJsonIndex); // rootJsonIndex = 0. // Set "id" at root JSON object. wsValue := "machine_1"; jsonBuilder.SetKeyWithValue("id", wsValue, diParentIndex := rootJsonIndex); // JSONData KEY: diParentIndex = 0 & diIndex = 1, VALUE: diParentIndex = 1 & diIndex = 2. // ... Time passes, we get our first reading to add ... // The "readings" array does not exist yet, so we make it first at root JSON object before adding our first reading. readingsJsonArrayIndex := jsonBuilder.SetKeyWithArray("readings", diParentIndex := rootJsonIndex); // JSONData KEY: diParentIndex = 0 & diIndex = 3, VALUE: diParentIndex = 3 & diIndex = 4. // Then add the first reading, for which we first have to make an object. readingsJsonArrayObjectIndex := jsonBuilder.SetObject(diParentIndex := readingsJsonArrayIndex); // JSONData OBJECT: diParentIndex = 4 & diIndex = 5. // And then we add the field(s) in the object for the first reading. // NOTE the use of `readingsJsonArrayObjectIndex` so we set the field(s) in the first object in the array. rValue := 153.8; jsonBuilder.SetKeyWithValue("temp_mid", wsValue, diParentIndex := readingsJsonArrayObjectIndex); // JSONData KEY: diParentIndex = 5 & diIndex = 6, VALUE: diParentIndex = 6 & diIndex = 7. // ... Time passes, we want to add another root-JSON-level field ... // Set "status" at root JSON object. wsValue := "RUNNING"; jsonBuilder.SetKeyWithValue("status", wsValue, diParentIndex := rootJsonIndex); // JSONData KEY: diParentIndex = 0 & diIndex = 8, VALUE: diParentIndex = 8 & diIndex = 9. // ... Time passes, we want to add a second reading ... // "readings" array exists, so add the second reading, but first we have to make another object. // NOTE the re-use of the earlier stored `readingsJsonArrayIndex`, so we add the new object to that previously created array. readingsJsonArrayObjectIndex := jsonBuilder.SetObject(diParentIndex := readingsJsonArrayIndex); // JSONData OBJECT: diParentIndex = 4 & diIndex = 10. // And then we add the field(s) in the object for the first reading. // NOTE the use of `readingsJsonArrayObjectIndex` so we set the field(s) in the SECOND(, new) object in the array. rValue := 98.3; jsonBuilder.SetKeyWithValue("temp_mid", wsValue, diParentIndex := rootJsonIndex); // JSONData KEY: diParentIndex = 10 & diIndex = 11, VALUE: diParentIndex = 11 & diIndex = 12. // ... Finally, we want to send to the API, so we must convert the builder to data the client accepts as a body ... xTestWriteToJsonArray := TRUE; jsonArrayWriter( xExecute := xTestWriteToJsonArray, pwData := ADR(jsonDataString), udiSize := SIZEOF(jsonDataString), jsonData := JsonData^ ); IF jsonArrayWriter.xDone THEN // The writer was successful, the `jsonDataString` VAR should now contain a WString copy of the JSON object from the builder. xTestWriteToJsonArray := FALSE; END_IF We see that the JsonData STRUCT is correctly organised (in terms of the diParentIndex & diIndex set by it for each JsonElement) as we expect, as outlined in my comments in the simplified code above. However, as soon as we pass it to the jsonArrayWriter (which is a JSON.JSONByteArrayWriter), the resulting jsonDataString does not match our expectations, instead coming out like this: { "id": "machine_1", "readings": [ { "temp_mid": 153.8 } ] } { "temp_mid": 98.3 } "status": "RUNNING" The behaviour of the JSONByteArrayWriter thus seems to be the problem here. It does not seem to correctly process the children of JsonElements that are ARRAYs when additions to them are done broken up by additions to the lower level JSON OBJECT they are a part of. We have confirmed this by changing the order of the calls in our example to add both readings before adding the "status", in which case we get our expected outcome. However, in reality this is not possible for us - additions to any of the JSON's objects, arrays or array objects may happen at any time after other fields elsewhere in the JSON have been added. Does anyone know a way around this, a fix, or knows a solution we simply have not found? This same phenomenon was also noted on this forum by user @ryusoup at the end of 2023 (https://forge.codesys.com/forge/talk/Engineering/thread/c45929e2f1/#e27f) and user @mtho in early 2024 (https://forge.codesys.com/forge/talk/Engineering/thread/cd1bb450db/#1292) but both topics received no activity beyond both users' opening posts. Looking through the release notes of all the versions of the JSON Utilities SL library, I also did not see any remarks on resolutions of bugs in this vain. Thanks in advance for the assistance!
Last updated: 2026-06-10

Post by timvh on Get Alarm status in Codesys ^{CODESYS Forge talk (Post)}
You are right, that you can use the GetState method, but it is not that simple. You first have to get a list of (filtered) alarms from the AlarmManager. You can find an example in Forge how to do this. See https://forge.codesys.com/prj/codesys-example/alarm-manager/home/Home/ Then you can go through this list to get the state of all the (filtered) alarms. See below the code which you could use. This is all based on the example from forge. Create a program: // This example shows how to access alarms via structured text. PROGRAM PLC_PRG VAR xInit : BOOL := TRUE; udiResult : UDINT; fbAlarmFilterCriteriaAll : FB_AlarmFilterCriteriaAll; fbAlarmManagerClient : FB_AlarmManagerClient; itfAlarmManagerClient : IAlarmManagerClient := fbAlarmManagerClient; xAlarm1 : BOOL; xAlarm2 : BOOL; xWarning : BOOL; iNrOfAlarmsInAlarmList : INT; iNrOfActiveAlarmsInAlarmList : INT; paitfAlarm: POINTER TO ARRAY [0..0] OF AlarmManager.IAlarm; iAlarmIndex : INT; eAlarmState: AlarmManager.AlarmState; END_VAR IF xInit THEN xInit := FALSE; fbAlarmManagerClient.itfAlarmFilterCriteria := fbAlarmFilterCriteriaAll; // register alarm client to get updated about alarm status / changes udiResult := AlarmManager.g_AlarmHandler.RegisterClient(itfAlarmManagerClient, 0, 0); END_IF // Polling the number of alarms udiResult := AlarmManager.g_AlarmHandler.GetActiveAlarms(itfAlarmManagerClient, parritfActiveAlarms => paitfAlarm, iCountActiveAlarms => iNrOfAlarmsInAlarmList); iAlarmIndex := 0; iNrOfActiveAlarmsInAlarmList := 0; WHILE iAlarmIndex < iNrOfAlarmsInAlarmList DO eAlarmState := paitfAlarm^[iAlarmIndex].GetState(); IF eAlarmState = AlarmManager.AlarmState.Active OR eAlarmState = AlarmManager.AlarmState.ActiveAcknowledged THEN iNrOfActiveAlarmsInAlarmList := iNrOfActiveAlarmsInAlarmList + 1; END_IF iAlarmIndex := iAlarmIndex + 1; END_WHILE See below some details about the function blocks: One function block should implement the IAlarmFilterCriteria interface. This can be empty except a few methods. FUNCTION_BLOCK FB_AlarmFilterCriteriaAll IMPLEMENTS AlarmManager.IAlarmFilterCriteria Method implementation (others related to interface are empty) METHOD AreAllAlarmClassesSelected : BOOL AreAllAlarmClassesSelected := TRUE; METHOD AreAllAlarmGroupsSelected : BOOL AreAllAlarmGroupsSelected := TRUE; METHOD GetPriorityFrom : USINT GetPriorityFrom := 0; METHOD GetPriorityTo : USINT GetPriorityTo := 255; The other function block should implement IAlarmManagerClient and get a reference to the FB which implements the IAlarmFilterCriteria FUNCTION_BLOCK FB_AlarmManagerClient IMPLEMENTS AlarmManager.IAlarmManagerClient VAR_INPUT itfAlarmFilterCriteria: AlarmManager.IAlarmFilterCriteria; END_VAR Method implementation (others related to the interface are empty) METHOD GetFilterCriteria : AlarmManager.IAlarmFilterCriteria // see VAR_INPUT for filter GetFilterCriteria := itfAlarmFilterCriteria; Off course you have to add the AlarmManager to your application and add some alarms to it.
Last updated: 2025-09-02

Post by gunstr on CODESYS control on RPi starts, shortly runs, then exits ^{CODESYS Forge talk (Post)}
I now tried to install 4.17.0.0 on a fully clean installations: A brand new RPi 4B Install latest Raspberry Pi OS Lite, Release date 13 May 2025, 64bit run sudo apt update && sudo apt full-upgrade When asked - Select to install the updated version of '/etc/initramfs-tools/initramfs.conf' Install CODESYS Control for Raspberry Pi SL. version 4.17.0.0 Log output: [INFORMATION] Connected successfully! [INFORMATION] Successfully connected to target (192.168.0.197) [WARNING] No supported container engine found on device. You have to install a supported container engine to use Virtual Control. Please contact the Administrator of the device. [WARNING] Error detecting container architecture [INFORMATION] Finished reading device information [ERROR] Error output: /var/lib/dpkg/info/codesyscontrol.postinst: 88: check_legacy_extensionapi_folder: not found [INFORMATION] Standard output: Selecting previously unselected package codesyscontrol. [INFORMATION] Standard output: (Reading database ... 76772 files and directories currently installed.) [INFORMATION] Standard output: Preparing to unpack .../codesyscontrol_raspberry_4.17.0.0_all.deb ... [INFORMATION] Standard output: Unpacking codesyscontrol (4.17.0.0) ... [INFORMATION] Standard output: Setting up codesyscontrol (4.17.0.0) ... [INFORMATION] Standard output: make config rw [INFORMATION] Standard output: set folder permissions [INFORMATION] Standard output: prepare permissions [INFORMATION] Standard output: check legacy extension api folder [INFORMATION] Standard output: create and install daemon [INFORMATION] Standard output: codesyscontrol started [WARNING] Unable to detect Raspberry Pi Architecture. Setting armv6l as default, you can change this through the settings panel. [INFORMATION] Standard output: codesyscontrol stopped [ERROR] Expected exit value of command failed: expected 0, received 1 [WARNING] Error setting the Raspberry Pi Architecture [ERROR] Error installing codesyscontrol If I read the log correctly the control is actually installed but cannot start. I'm running out of ideas how to proceeed now, any suggestions are welcome.
Last updated: 2025-09-03

Post by youness on No source code available (cip object) ^{CODESYS Forge talk (Post)}
Hi yotaro, hope your problem was resolved. I had the same, but with an other library title. This exception is not detected during compilation, but rather at a given position in the program (when switching to a given visualization). Although the exception is generated at this point, it does not involve the visualization in question. This error is due to one of 3 reasons: 1) A division by zero somewhere: The program is able to detect divisions by zero at compile time. But in the case of a variable, which takes a valid value at init and changes to 0 at a later stage. 2) An invalid pointer: (either because it has a value of 0, or because it points outside the memory reserved for the program) is being dereferenced. Locate any pointers or interfaces you have in the code and check them - you should also be wary of mixing inline modifications and pointers. 3) Array overflow: Generally when a processing operation is executed outside the array's definition range. Example: a write loop with n iterations is executed on an array of dimmension n-1. On the other hand, the error message may not appear. In the latter case, the error may have fatal consequences, as the overflow has induced writing to potentially forbidden memory areas. This problem can be explained by the fact that it's not always the adjacent memory areas of PLC_PRG that are overwritten, but the memory areas that are randomly allocated to the array during compilation. In this case, however, there is no entry in the log, so you need to integrate the "Implicit Check function", which checks the line of code generating the error. To integrate this functions, click on Application --> POU for implicit controls Regards,
Last updated: 2024-07-16

Post by tk096 on Some 'pathetic' errors in SoftMotion program ^{CODESYS Forge talk (Post)}
Meanwhile, I would like to understand why the motion FB instances must still be called even after the Execute is set to FALSE, especially in view of the fact that the next instruction is programmed to abort the previous one, with BufferMode set to 'Aborting'. All these unnecessary FB calls are an unnecessary overhead on the CPU anyway. Is there any precise rule about when to cease calling the various instances? (It should precisely be the 'done' status that says this one has finished its work). In general: - Motion function blocks have to be called until they report 'Done', 'Error', 'CommandAborted' or a subsequent motion FB with BufferMode=Aborting is started in the current cycle. - Setting the Execute input to FALSE will not abort any ongoing motion of the motion function block. For example, one case that is often problematic is the execution of the Axis Halt instruction. When, after a MoveAbosulte instruction this returns the event as 'done' and indeed the axis is in standstill, the state machine first sets the move instruction to FALSE, and the next cycle sets the Halt request to TRUE. Some of the time everything works out fine. Occasionally, however, in this exchange, the axis goes into fault, also losing the OPERATIONAL state. I think the error SMC_FB_WASNT_CALLED_DURING_MOTION is only a follow-up (and misleading) error that results from the axis not being in operational state anymore (bus problems). Is there an error 'regulator or start not set' in the device log before the error 'motion generating FB wasn't called for at least one cycle'? Which error does the respective function block (Halt.ErrorId) report?
Last updated: 2024-07-22

Post by clarenced on Multiple applications on one device sharing variables. ^{CODESYS Forge talk (Post)}
I am looking for an example of how to run 2 applications on 1 device that would have global variables shared between the two apps. In this case what I am trying to do is to have the main program logic run as one application and then have the visualization run as a second application. I find this https://us.store.codesys.com/media/n98_media_assets/files/000013-F/0/Multiple%20Applications_en.pdf, that talks about exactly what I want to do, but I can't find the download. The main reason I want to do this is for download speed. Right now it takes at least a minute to download our application to the PLC. A simple program downloads to the PLC in a very short time, but add visualization and the download time gets much longer. If I could download the program separately from the visualization I think that a simple program change would take very little time to download. I have tried create a GVL in the POUs view. This partly works in that both applications can see the GVL, but they each create their own instance of it and the variables are not shared between the two apps. There are ideas of using OPCUA but this raises problems with licensing and having to move any variable that needs to be shared into the Symbol Configuration. This adds a lot of management to keep this up to date. Any ideas would be appreciated thanks.
Last updated: 2025-02-20

Post by rmarco on Generic Variables and FDB ^{CODESYS Forge talk (Post)}
Hello everyone, I am running into a highly frustrating issue in the FBD editor regarding a Function Block with generic constants (VAR_GENERIC CONSTANT). I created a FB using ST, with a generic var, useful for having a variable sized array, as follows: FUNCTION_BLOCK Coil VAR_GENERIC CONSTANT maxEvents: USINT := 5; END_VAR VAR events: ARRAY[0..maxEvents-1] OF IEvent; END_VAR These FBs have also several methods. I declare them as follows in code: VAR coil1: CDL.Coil<(maxEvents:=1)>; END_VAR and when using them in ST, I have no problems. However, when trying to use them in FDB, I do not know how to do that, as some strange misalignment happens. Here's what happens: When I add the block to my FBD canvas and assign coil1 as the instance name, the compiler throws this error: 'coil1' is not an instance of 'CDL.Coil<(maxEvents:=1)>'. Same occurs when I try to instantiate blocks such as 'coil1.turnOn' or similar. Here is what I have already tried, none of which worked: - Deleting the <(maxEvents:=1)> parameter from the text inside the FBD box. - Deleting the block entirely, dropping an "Empty Box", and typing coil1 above it to let the IDE auto-complete and format the block. - Running a full "Clean All" and rebuilding the code. I am aware that I could bypass the graphical editor by calling it in Structured Text. However, I need to keep this logic compatible to FBD. Has anyone encountered this specific FBD parsing bug with generic variables? Thanks in advance for any insights. Best regards, Marco
Last updated: 2026-06-29

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 arvind on communication ^{CODESYS Forge talk (Post)}
HI All past two weeks im trying to configure and establish communication between wago rs485 fieldbus coupler(750-315/300-000) with wago pfc 200 plc but not able to communicate can you peoples help me to configure and establish communication using codesys v3.5 and above
Last updated: 2023-08-19

Post by eschwellinger on Stop raspberry from executing a plc program ^{CODESYS Forge talk (Post)}
/var/opt/codesys/PLCLogic as soon you have dowloaded the project to the Pi it will run the bootapplication no connection to the pc is needed anymore
Last updated: 2023-08-24

Post by eschwellinger on Same program to more than one PLC ^{CODESYS Forge talk (Post)}
just open http://localhost:8080 in Chromium then it will show the webvisu ( sure you need to this in your CODESYS Application)
Last updated: 2023-08-24

Post by bagusd on gateway problem ^{CODESYS Forge talk (Post)}
hello, I have a problem with the gateway not being able to connect to the plc, does anyone know why the gateway is difficult to connect to the plc? even though the lan cable has been connected to the plc and codesys gateway V3 has been restarted, thank you
Last updated: 2023-08-25

Post by sedoerr on Warnung C0373 / Dialog nicht instanziert ^{CODESYS Forge talk (Post)}
Hallo Leute, in meinem Projekt bekomme ich mehrfach folgende Warnung beim Übersetzen: C0373: Dialog <visudialogs.textinputwithlimits> ist in der Applikation nicht instanziert. Fehlt er im Visualization Manager?</visudialogs.textinputwithlimits> Was genau möchte mir Codesys damit sagen bzw. wie bekomm ich diese Warnung behoben? MFG
Last updated: 2023-08-29

Post by roundex on CSVReaderInit returns error : INVALID_HANDLE ^{CODESYS Forge talk (Post)}
I got same issue but managed to get it to work again by downgrading the Runtime. Here's my specs: CODESYS V3.5.19.0 Runtime Linux SL 4.7.0.0. CSV Utility SL 1.1.0.0 (Licensed IIoT libraries SL) I tried Runtime 4.8.0.0. and 4.9.0.0 but both result in INVALID_HANDLE error.
Last updated: 2023-08-30

Post by eschwellinger on Device User Logon and No device is responding.. Pi4b codesys 3.5 SP19 2 + (64-bit) ^{CODESYS Forge talk (Post)}
please use latest version 4.9.0.0 and it is mandatory to have a user pi on your device.
Last updated: 2023-09-11

Post by transmin01 on CANbus issue ^{CODESYS Forge talk (Post)}
Hi, I have been trying to get a CANbus device working with Codesys 3.5SP19 patch1 via a Beckhoff EL6751 gateway without success. I have the CANOpen_Manager and CANopen device configured but this will not run. Is there any code required to kickstart the CANbus comms into action? Regards Trevor
Last updated: 2023-09-13

Post by chris12345 on OPC UA datasource low read frequency ^{CODESYS Forge talk (Post)}
Hi yr00, the default sampling interval is set to 1s. you can generate your own client settings, this link should help you:- https://content.helpme-codesys.com/en/CODESYS%20Communication/_comm_use_dynamic_opc_ua_server_comm_settings.html
Last updated: 2023-09-13

Post by chris12345 on OPC UA datasource low read frequency ^{CODESYS Forge talk (Post)}
Hi yr00, the default sampling interval is set to 1s. you can generate your own client settings, this link should help you:- https://content.helpme-codesys.com/en/CODESYS%20Communication/_comm_use_dynamic_opc_ua_server_comm_settings.html
Last updated: 2023-09-13

Post by chris12345 on Calling OPC UA Methods from UaExpert ^{CODESYS Forge talk (Post)}
Hi, Is it possible to generate an .xml file with FBs and methods from Codesys? Or do I need a separate program to generate the .xml file? Or is there a otherway to use methods via opc ua from the own project?
Last updated: 2023-09-20

Post by fleaplc on FILE_OPERATION_DENIED ^{CODESYS Forge talk (Post)}
By using the CAA FILE library (FB FILE.Open) (raspberry pi, codesys 3.5.19.0) I always get the error FILE_OPERATION_DENIED The file exist, it has r/w/x access and path is correct... Some idea to fix it?
Last updated: 2023-09-25

Post by rschwager on description about the build compiler definition ^{CODESYS Forge talk (Post)}
Hi CODESYS moderators and user! Is there any description about the compiler definition in property of application? e.g.: CANOPEN_NO_HEARTBEATPRODUCING Is there more definition? Best regards Robert
Last updated: 2023-09-26

Post by simond on The required device description is not installed.. ^{CODESYS Forge talk (Post)}
Hi folks, can someone please tell me how to go about fixing this issue? I am getting this error when I implement an instance of the J1939_Manager. Thanks Simon
Last updated: 2023-10-03

Post by tomas111 on Help with error C0142 ^{CODESYS Forge talk (Post)}
There was an exact mistake. I did as they wrote. I created a visualization and transferred it from the old one and everything works. CS 3.5 SP 19. Thank you.
Last updated: 2023-10-04

Post by sivakov on Change the default ssh port ^{CODESYS Forge talk (Post)}
Of course there is! =) just edit file/etc/ssh/sshd_config and restart ssh service. but you'll lose the possibility of runtime management through "update Linux", so there enother question - how to change default port in codesys it-self?
Last updated: 2023-10-11

Post by damian177 on Delete PLC Log ^{CODESYS Forge talk (Post)}
You already know how clear log ? In codesys I am reading twenty Modbus TCP Devices. When several of those doesn't response , the logs is grovs very fast and my PLC hangs.
Last updated: 2023-10-16

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