Post by akrawczyk on Dynamically enabling/disabling Modbus slave devices in runtime (performance issue with timeouts) ^{CODESYS Forge talk (Post)}
Hi everyone, I'm working on a CODESYS-based project running on a Weintek cMT2078X HMI with a built-in CODESYS runtime. The system communicates with multiple Modbus RTU slave devices, arranged in a cascade. The number of connected units can vary between 2 and 8, depending on the installation. Each slave has 17 Modbus channels, which are polled cyclically every 5 seconds. The issue is that when fewer devices are physically connected (e.g. only 3 out of 8), the Modbus master still attempts to communicate with all configured slaves. This leads to massive delays due to timeouts (currently 200ms per channel). For one disconnected device, that’s: 17 × 200ms = 3.4 seconds of delay per polling cycle, and this quickly multiplies with each additional missing slave. This behavior significantly degrades the system's performance and responsiveness. We attempted a workaround where we tried to trigger polling based on a variable in the PLC program, but this caused instability and even led to hardware hangs/freezes on the cMT2078X – likely due to clashes in how the Modbus polling engine and program logic interact at runtime. My main questions are: Is there a way in CODESYS to dynamically enable/disable Modbus slave devices at runtime, using a BOOL or INT variable (e.g. indicating number of active slaves)? Can devices or channels be conditionally polled or temporarily disabled without removing them from the device tree? Are there any best practices or examples for handling variable numbers of Modbus slaves in scalable systems like this? Would splitting communication across tasks or interfaces help reduce the impact of timeouts? Any advice, documentation references, or architectural suggestions would be extremely helpful. I'm looking for a robust way to dynamically scale slave polling without degrading system stability or performance. Thanks in advance!
Last updated: 2025-08-11

Post by akos on Soft motion kinematic zones ^{CODESYS Forge talk (Post)}
Hello Everyone, Is there any solution to define safety/forbidden zones in the coordinate system of the kinematics? Its not enough, to define only limits in my servo axes! I need zones in 3D! :) Thanks for the help!
Last updated: 2024-07-10

Post by timvh on PHOENIX CONTACT Axioline PLCnext project in CodeSys SodftPLC ^{CODESYS Forge talk (Post)}
In the device selection. Do not filter on Phoenix. Remove this filter and first add an Ethernet Adapter from CODESYS. To this Ethernet adapter add the Profinet Controller. After this you can filter on Phoenix devices in the "add device dialog".
Last updated: 2025-09-09

Post by pernockham on Unable to deploy "Control for Linux SL 4.18.0.0" ^{CODESYS Forge talk (Post)}
Am I alone in this? Is this a known fault? Should I look for the reason of the lacking update option for "Control for linux SL" in my system or is it a potential fault in the codesys system?
Last updated: 2026-02-17

Post by manuknecht on Persistence Manager does not save alphabetically first value ^{CODESYS Forge talk (Post)}
After some more digging I realized that I get an error on the PLC Logger saying PersistenceChannel: 150 (invalid type in data: SimpleLibrary). I suppose the issue could be found in the ConfigData, which is automatically generated and which looks like this: 1 9##83 SimpleLibrary#GVL.aMoreZeros.[1]#0#64512#15#0 <[2]#0#64520#15#0 <[3]#0#64528#15#0 <[4]#0#64536#15#0 <#0#64544#15#0 <[6]#0#64552#15#0 <<lrVar#0#64560#15#0 <strVar#0#64428#16#80 <uiDummy#0#64370#11#0 Perhaps the fact that the variable is stored within a library confused the compiler? I tried changing the PersistenceChannel parameters to xCompressTags := FALSE which changed the entry in the data file from _xCompressTags BOOL:TRUE _xCompressTags BOOL:FALSE but the actual content of the data file and also the config data did not change.
Last updated: 2023-10-17

Post by salvatorethomas on Port instantiation of serial interface in WAGO PLC using Modb_L05.lib in CoDeSys v2.3 ^{CODESYS Forge talk (Post)}
Hi — good description of the problem. A few suggestions / questions that might help narrow this down: Since your first serial port (COM2) works fine but the second (COM4 + MODBUS_EXT_MASTER) never opens, check whether the two ports are truly independent — some WAGO modules share internal resources, so COM4 might conflict with other functions or modules. Make sure that the physical wiring and module configuration for the second port (baud rate, flow control, RS-485 vs RS-422, etc.) exactly match what the library expects — a mismatch in flow control or wiring could prevent port opening even if the LED signals seem OK. Try using a plain SERIAL_INTERFACE on COM4 first (like you did for COM2) without Modbus logic — if that opens, you know the hardware + port config is fine, so the issue is more likely with modb_L05.lib. If the port opens but Modbus still fails, enable debug/logging (if available) to inspect whether the port opening fails or the subsequent Modbus negotiation fails. If you like — I can share a minimal example project I used with WAGO + COM4 + Modbus that worked; you could adapt that to test your setup. Wacky Flip
Last updated: 2025-12-01

Post by bartg on Open a POU in the editor via scripting ^{CODESYS Forge talk (Post)}
Hi, I would like to automate opening some specific pous and visualisations in the codesys environment I found out that I can open it by using : system.commands["42f6acb9-bd6e-42e7-94bb-6e2a03973b83"].execute() But the POU has to be selected in the Devices or POUs navigator. Does anyone know how I can select a specific POU in the navigator? Or how I can open a specific POU? I can retreive the guid of the POU. Thx
Last updated: 2024-05-30

Post by timvh on History of Alarms ^{CODESYS Forge talk (Post)}
It is most likely related to the existing alarm log files in the Control Win. Depending on how you start up the Control Win, you can find the files in: C:\Users\<user name="">\AppData\Roaming\CODESYS\CODESYSControlWinV3x64\<unique id="">\PlcLogic\alarms\ Or C:\Windows\System32\config\systemprofile\AppData\Roaming\CODESYS\CODESYSControlWinV3x64\<unique id="">\PlcLogic\alarms\</unique></unique></user> Delete the files in this folder, download your project again and start the application. PS, if you have an older version of CODESYS, the files are in: C:\ProgramData\CODESYS\CODESYSControlWinV3x64\<unique id="">\PlcLogic\alarms</unique>
Last updated: 2026-01-07

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 tyronnosaurus on ReceiveWatchdog FB not working on J1939 P2P PGNs ^{CODESYS Forge talk (Post)}
Hi guys. I've got a device that sends a status message over J1939 and a PLC running Codesys to receive it. This message uses a P2P PGN (as opposed to a broadcast PGN). Codesys can only read it if I mark the J1939_ECU as "Local" (see screenshot 1). The message is received correctly, that is not the problem. The problem is detecting if the message stops being received. Local ECUs have no Watchdog checkbox to detect if the message has been received in the last X seconds. In order to implement a watchdog, I've used a ReceiveWatchdog FB. The same code works well for any non-P2P message, but doesn't work for this particular P2P message I'm trying to monitor. Even if I physically disconnect the device, ReceiveWatchdog.xBusy stays True, and ReceiveWatchdog.xError never triggers due to a timeout error. Is there any caveat in the ReceiveWatchdog FB that makes it unable to monitor P2P PGNs in Local J1939_ECUs?
Last updated: 2024-07-11

Post by mp9876 on Problem using MeasureFrequence FB ^{CODESYS Forge talk (Post)}
Hi everyone, new at Codesys and PLC programming in general. I am using Codesys Win V3.5 SP20 I would like to measure an encoder's frequency output (obtaining that pulse train from Factory IO) and intended to use the MeasureFrequence FB (Intern/CAA/Utilities/CAA Mathematics/3.5.19.0). As mentioned in the title what I need to measure is low frequency, such as lower than 40hz (a cycle every 25mS) or so; I could even go lower frequency if required as this is for test purposes) therefore I am not expecting problem measuring a low frequency with that FB The library in question appears to be installed as I can retrieve it from the Library Repository. I can also see it from the Device's Library Manager. Problem arises when I am trying to instantiate this particular FB. I go like this: VAR MeasF:MeasureFrequence; END_VAR Please note that as soon as I start typing the "MeasureFrequence", the MeasureFrequence comes out as a viable option in auto-typing; seems to indicate that the FB is recognized somehow. But there is no way I can compile this as it comes back with the following: C0046: Identifier 'MeasureFrequence' not defined. Tried to rename that to ABC instead of MeasF; same issue. Possibly that the library is not properly installed ? Placeholder ? I would greatly appreciate a bit of guidance if possible. Thank you and regards, Mike
Last updated: 2024-06-24

Post by c3po on Wago PLC Disable Device Login ^{CODESYS Forge talk (Post)}
is there also a possibility to deactivate the login screen from the Hmi if you transfered a new project? I send the screen as attachment:
Last updated: 2024-10-09

Post by vkira on Radio module on wago 750-8217 ^{CODESYS Forge talk (Post)}
Hello. Tell me how to connect to the internal radio module PLC 750-8217. I use the gsm sms_01 library. I don't understand how to connect. via com port? what's the address?
Last updated: 2024-05-06

Post by hfelek on TargetVisu for Linux Package on runtime 4.12.0.0 install error due to Qt dependencies. ^{CODESYS Forge talk (Post)}
Hi, I am trying to make my runtime support TargetViso on 4.12.0.0 runtime. First when I tried to install package I got error due to missing libraries that are generated through qt-base. After compiling and installing related qt lib when I tried to install the package, I didnt get lib dependencies error but I got another error: [ERROR] The installed QT Version does not meet the minimum required version 6.4.2. Please install version 6.4.2 or higher and try again. When I check Qt version I get the following response QMake version 3.1 Using Qt version 6.5.0 in /usr/local/qt6/lib. I tried with Qt version 6.9.0 but that didn't help. Any idea on what coudl be the reason. When I looked for codesys related processes the related libraries were included within environment.
Last updated: 2024-08-27

Post by wbj0t on System libs and I/O Drivers ^{CODESYS Forge talk (Post)}
Hi everyone. My question about: where I can learn (read or watch) an info about codesys workflow through the system IO libs? I want to know how to implement I/O drivers by my self. In the system libs I see many interfaces, methods etc... But there is no explanation about them, just names of methods and fields of the FBs. I know about this page: https://forge.codesys.com/drv/io-drivers/doc/Generic/ There is so BIG the device description file and not so clear explaining of the attributes and elements, also some elements or attributes missed at it all. Yes, there are code examples on this page, but, so shortly and, for example, code about Modbus drivers is absent. And even if I try to add the IoDrvFB with lib, I get and error, something like: "failed to load IoDrvFB driver". And what about the book of codesys that written by Gary Pratt? Is there information about system libs and drivers in this book more clearly? Thank you :)
Last updated: 2024-02-02

Post by george32 on Readable IO names ^{CODESYS Forge talk (Post)}
Hello Folks, I have a quite basic understanding of how PLC programming works. However I keep getting stuck on 1 problem I could not get my head around. The problem is as follow: I have a PLC with 60 IO (20 inputs, 40 outputs). Each IO is defined as a function block. Furthermore I have an external IO card connected trough a CanBus connection. This IO card has 4 analog input channels (USINT), 4 digital inputs (Bool) and 4, digital outputs (Bool) Because I have 2 different components which both has data have I made 4 arrays to store the data off every component in one variable. PLC_Input: Array [1..20] of BOOL; PLC_Output: Array [1..40] of BOOL IOCard_Input: Array [1..8] of BOOL IOCard_Output: Array [1..4] of BOOL Because the control and reading of the different in and outputs is done by a TCP connection I want to use some kind of enumeration or struct to give each index a name so that my main would be a little bit more readable instead of all the magic numbers. Also this would make my program more dynamic for the furter in case I need to changes some in the IO nummers. For example: pump is placed on the fysical terminal strip number place 54, which is the 3th output of the IO card in the program: if I am sending a message with value 54 I would like to control IOCard_Output[3]. If there is a solution or methode to get this done, I can eventually do the following in my main program: IOCard_Output[Pump]. I have tried the following: IOCard_Output[Pump - 51] with an enumration but this keeps raising an error I hope some of you could help me further with this problem. In gross lines: I want to couple all the different IO to a more readable name and this readable name should control the right Array index Thanks in advance, George
Last updated: 2024-09-26

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 eschwellinger on Licensing info not available. ^{CODESYS Forge talk (Post)}
yes and no ... if you run the license server on the host (to serve licenses to the docker instances / vplcs then there is no runtime which could check the licenses on the host. Therefore you need the CODESYS WBM to activate or check the licenes or you could use in CODESYS IDE the licensemanager ( not the one for the device licenses) but you have the the IP of the license server that he know where to search for the licenses ..tool options i guess to add it, will add a screenshot later.
Last updated: 2025-10-01

Post by smercante on Unable to Import PLC Open XML from Easy Remote IO ^{CODESYS Forge talk (Post)}
Hello dear. I have the same problem. Could you solve it? Do you use GLV variables?
Last updated: 2023-08-24

Post by gregor on PFC 200 - codesys V3.5 ^{CODESYS Forge talk (Post)}
As far as I know, only if someone downloaded sourcecode to the PLC.
Last updated: 2023-08-25

Post by megamax on Codesys + BeagleBone PLC +LED control ^{CODESYS Forge talk (Post)}
Hello! Did you ever solve this? I'm running into the exact same problem.
Last updated: 2024-08-12

Post by liamb on Unable to add alarm configuration object to project ^{CODESYS Forge talk (Post)}
Yep that was the case, PLC didn't support it.
Last updated: 2024-09-27

Post by eschwellinger on Update Raspberry Pi option is missing under Tools menu ^{CODESYS Forge talk (Post)}
The new Deploy Tool 4.14.0.0 contains all devices. Raspberry PI virtual plc etc.
Last updated: 2024-12-13

Post by nz-dave on Ethernet/IP Scanner Exception ^{CODESYS Forge talk (Post)}
Its Running on a Weintek CMT HMI. the program is not huge, just controlling a few pumps. plc is at 1%
Last updated: 2024-12-27

Post by runtimevictor on virtual plc vPLC configure nics ^{CODESYS Forge talk (Post)}
Hello @eschwellinger, I have tried version 4.13.0.0 and the same thing happens to me...
Last updated: 2025-02-03

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