Post by oymyakon on Modbus Lockup ^{CODESYS Forge talk (Post)}
Hi i have a project where i am communicating with many modbus devices using TCP to serial. This is all working extremely well except when i turn one of the remote devices off. If i leave the auto reconnect on it still doesn't talk to the rmianing devices and if i turn Auto reconnect off it locks up. Any help would be appreciated. Paul.
Last updated: 2024-08-07

Post by oymyakon on Modbus Lockup ^{CODESYS Forge talk (Post)}
Hi i have a project where i am communicating with many modbus devices using TCP to serial. This is all working extremely well except when i turn one of the remote devices off. If i leave the auto reconnect on it still doesn't talk to the rmianing devices and if i turn Auto reconnect off it locks up. Any help would be appreciated. Paul.
Last updated: 2024-08-07

Post by fmon on Modbus TCP client reconnection problem ^{CODESYS Forge talk (Post)}
Hello, I am using codesys Modbus TCP client (4.4.0.0) to communicate with a python modbus server (package pyModbusTCP). I first start my python server on the distant machine. After a fresh codesys compilation, a plc connection/transfer and a PLC run, the modbus connection is OK. Every time in this context the connection is created correctly. When I shut down the server, the modbus connection falls, that is normal. When I restart the python server, impossible to recreate the modbus connexion. With the client autoreconnection, I see on my server that the client tries to connect but unsuccesfully. I have the following message : DEBUG:pyModbusTCP.server:accept new connection from ClientInfo(address='192.168.1.20', port=33476) DEBUG:pyModbusTCP.server:Exception during request handling: NetworkError('recv return null') I tried to stop the codesys client and to restart it with these commands : Modbus_TCP_Client.xStop := True; // Or False Modbus_TCP_Client.Enable := True; // Or False Modbus_TCP_Server.Enable := True; // Or False I tried to confirm the error manually to force reconnection with: Modbus_TCP_Server_Motors.xConfirmError := TRUE; I tried also this command to STOP/RESET/START client and server (codesys side) but nothing happens : status_client := Modbus_TCP_Client.SetCommunicationState(eRequestedState := DED.DEVICE_TRANSITION_STATE.STOP); // .RESET & .START The answer of this function when executed is "status_client = NOT_SUPPORTED". Is it normal ? It seems that is a socket problem, but I do not understand if it is on the client or server side. I tried a modbus simulator called "ananas.exe" and the result is the same. Impossible to get a modbus client reconnection. What is different at the first client connection and at a reconnection attempt ? Thanks for your help
Last updated: 2025-03-17

Post by sking on ModbusTCP/slave ^{CODESYS Forge talk (Post)}
i can not find the solution, i have 2 modbus tcp slave and i want to know how to do when one is activated the other one is desactivated. that means when i run the project, with a bouton click on my web visu i can choose wich modbus slave i want to activate. can someone have a solution plz ? thank you :)
Last updated: 2025-04-01

Post by sandro66 on Application-based license Modbus Channels ^{CODESYS Forge talk (Post)}
Hi, I imported an old project created with version 3.51.20.50 into the new version 3.51.21.20. I'm using ModbusFB.ClientTCP v4.5.0.0. Strangely, I can no longer download the project due to a licensing issue I didn't have before. The number of Modbus channels has gone from 1 to 54!, and there's no license that would work. Can anyone tell me where I'm going wrong? Thanks Sandro
Last updated: 2025-08-27

Post by nano on Modbus TCP/IP slave communication errow ^{CODESYS Forge talk (Post)}
please tell us the exact error message from diagnostic. U can view it at devicetree in the node-element diagnostic from modbus-configuration. u also can activate the function auto-reconnect in master and increase a little bit the timeout and the repetition to male thw communication a little bit more robust
Last updated: 2024-02-04

Post by squiggleypuff on Can't Add New Version of Modbus TCP Master ^{CODESYS Forge talk (Post)}
I'm having a tough time trying to get Modbus working on a Festo CPX-E PLC; it throws these pre-compiler errors as soon as I add in my Modbus TCP Master 3.5.12.30 to my project: I'm confused about the C0046 error, as I have IODrvModbusTCP 4.3.0.0 Library installed. So I thought maybe I needed to use the newest Modbus TCP Master 4.3.0.0, which is in my device repository: However, whenever I go to add this underneath the Ethernet adapter (which is version 4.2.0.0), the only TCP Master version available is the old 3.5.12.30 one, even if I have Display all versions checked.: I even went so far as to delete the old version, but then there were no options to add a Modbus TCP Master under my Ethernet adapter. What needs to be done to use the newest Modbus TCP Master? Or are these pre-compiler errors unrelated and I'm missing something? Any help greatly appreciated.
Last updated: 2024-04-04

Post by ewi04 on Git - User identification data is lost when codesys is closed ^{CODESYS Forge talk (Post)}
Hallo, it's not a big problem, but it is a bit annoying. The git user identification data is lost when codesys is closed. So I have to enter the information again and again. Is there a way to save the data? Environment: Codesys V3.5 SP19 Patch 4 (64Bit), Git 1.3.0.0 Thanks
Last updated: 2023-11-22

Post by fazlinda on AWS IoT core CODESYS ^{CODESYS Forge talk (Post)}
Hi, Im having a problem sending a data from my structure text code from codesys to aws. Instead of receiving {state {reported {data: 123}}} It display {state {reported {data: 123}}}\x00 \x00 \x00 \x00 \x00 \x00 \x00 Please help me solve this issues. how to remove \x00 ?
Last updated: 2023-12-06

Post by fazlinda on AWS IoT core CODESYS ^{CODESYS Forge talk (Post)}
Hi, Im having a problem sending a data from my structure text code from codesys to aws. Instead of receiving {state {reported {data: 123}}} It display {state {reported {data: 123}}}\x00 \x00 \x00 \x00 \x00 \x00 \x00 Please help me solve this issues. how to remove \x00 ?
Last updated: 2023-12-06

Post by fazlinda on AWS IoT core CODESYS ^{CODESYS Forge talk (Post)}
Hi, Im having a problem sending a data from my structure text code from codesys to aws. Instead of receiving {state {reported {data: 123}}} It display {state {reported {data: 123}}}\x00 \x00 \x00 \x00 \x00 \x00 \x00 Please help me solve this issues. how to remove \x00 ?
Last updated: 2023-12-06

Post by fazlinda on AWS IoT core CODESYS ^{CODESYS Forge talk (Post)}
Hi, Im having a problem sending a data from my structure text code from codesys to aws. Instead of receiving {state {reported {data: 123}}} It display {state {reported {data: 123}}}\x00 \x00 \x00 \x00 \x00 \x00 \x00 Please help me solve this issues. how to remove \x00 ?
Last updated: 2023-12-06

Post by fazlinda on AWS IoT core CODESYS ^{CODESYS Forge talk (Post)}
Hi, Im having a problem sending a data from my structure text code from codesys to aws. Instead of receiving {state {reported {data: 123}}} It display {state {reported {data: 123}}}\x00 \x00 \x00 \x00 \x00 \x00 \x00 Please help me solve this issues. how to remove \x00 ?
Last updated: 2023-12-06

Post by fazlinda on AWS IoT core CODESYS ^{CODESYS Forge talk (Post)}
Hi, Im having a problem sending a data from my structure text code from codesys to aws. Instead of receiving {state {reported {data: 123}}} It display {state {reported {data: 123}}}\x00 \x00 \x00 \x00 \x00 \x00 \x00 Please help me solve this issues. how to remove \x00 ?
Last updated: 2023-12-06

Post by abjha1998 on Converting UINT into bytes and converting 2Bytes into UINT ^{CODESYS Forge talk (Post)}
Hi, I have been working on Codesys V3.5 with PFC200 controller and Can Gateway 750-658. I want to convert the incoming CAN data from bytes into UINT and for outgoing data bytes to UINT. Does anyone has experience with this kind of data? I tried few different ways but it doesn't seem to be working.
Last updated: 2023-12-07

Post by dengsberg on Check Connection Status of the OPC-UA Server for Data Source Manager with OPC-UA Client ^{CODESYS Forge talk (Post)}
I am using the Data Source Manager with OPC-UA Client to get data from another CodeSys application in the same Project. How can I check in the PLC_PRG structured text if the connection is ok or not?
Last updated: 2024-09-07

Post by mubeta on UNION statement is not supported in the ethercat data exchange ^{CODESYS Forge talk (Post)}
Hi all, I am using a unionn statement for merge in integer data type some values that are received in byte from the i/o cards, but, using this simple and light technique, is not recognized by the ethercat data exchange and in fact the tags are not updated. In my opinion it's a very big bug.
Last updated: 2025-02-05

Post by nima-khajehali on Data Transferring between 2 PLCs in a same PC ^{CODESYS Forge talk (Post)}
Hi Guys, I want to simulate the data exchange between 2 soft PLCs on the same PC. We are trying to simulate the process and we could not see the desired result. What should I do to pass all data between these 2 PLC's correctly ? Please see attached
Last updated: 2024-02-05

Post by timvh on Send data to USB ^{CODESYS Forge talk (Post)}
https://forge.codesys.com/prj/codesys-example/file-utilities/home/Home/
Last updated: 2024-07-22

Post by vladimirsmall on Send data to USB ^{CODESYS Forge talk (Post)}
Thank you on support
Last updated: 2024-08-05

Post by robbudge on Data Source Error 418 ^{CODESYS Forge talk (Post)}
Same ? Did you find the Solution??
Last updated: 2024-10-11

Post by installwhat on Unable to select VisuDialogs.Numpad in Open Dialog input configuration ^{CODESYS Forge talk (Post)}
data type?
Last updated: 2025-07-16

Post by grepoo on Data Source Error 418 ^{CODESYS Forge talk (Post)}
Hi, Same error here, have you found any solution ? Thx
Last updated: 2025-11-14

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 wildcard on Modbus Client Request Not Processed ^{CODESYS Forge talk (Post)}
Hi, does anyone has a solution for this issue. I've the same problem. I've implemented a very simple client based on the Modbus Examples and connected the soft PLC to a Modbus Simulator. PROGRAM ModbusClient VAR initDone : BOOL := FALSE; errorID : ModbusFB.Error; client : ModbusFB.ClientTCP; timeout : UDINT := 500000; replyTimeout : UDINT := 200000; aUINT : ARRAY [0..8] OF UINT; clientRequestReadHoldingRegisters : ModbusFB.ClientRequestReadHoldingRegisters; clientRequestsCnt : UINT := 0; clientRequestsProcessCnt : UINT := 0; ipAddress : ARRAY[0..3] OF BYTE := [10,54,0,72]; END_VAR IF NOT initDone THEN initDone := TRUE; client(aIPaddr:=ipAddress, udiLogOptions:=ModbusFB.LoggingOptions.All); client(xConnect:=TRUE, ); clientRequestReadHoldingRegisters(rClient:=client, udiTimeOut:=timeout, uiUnitId:=1, uiStartItem:=0, uiQuantity:=4, pData:=ADR(aUINT[0]), udiReplyTimeout:=replyTimeout); clientRequestReadHoldingRegisters.xExecute := TRUE; clientRequestsCnt := 0; END_IF clientRequestReadHoldingRegisters(rClient:=client, udiTimeOut:=timeout, uiUnitId:=1, uiStartItem:=0, uiQuantity:=4, pData:=ADR(aUINT[0]), udiReplyTimeout:=replyTimeout, xExecute := TRUE); IF clientRequestReadHoldingRegisters.xError THEN clientRequestsCnt := clientRequestsCnt +1 ; errorID := clientRequestReadHoldingRegisters.eErrorID; END_IF clientRequestReadHoldingRegisters(rClient:=client, udiTimeOut:=timeout, uiUnitId:=1, uiStartItem:=0, uiQuantity:=4, pData:=ADR(aUINT[0]), udiReplyTimeout:=replyTimeout, xExecute := NOT clientRequestReadHoldingRegisters.xExecute); When the system is running I do get the following on the logs: 2024-05-13T10:18:07.443Z: Cmp=MODBUS lib, Class=1, Error=0, Info=0, pszInfo= Client.RequestProcessed ClientRequest,16#0164ADC561A0 unitId=1 fc=ReadHoldingRegisters id=2070 state=Error 2024-05-13T10:18:07.443Z: Cmp=MODBUS lib, Class=1, Error=0, Info=0, pszInfo= ClientRequest,16#0164ADC561A0 unitId=1 fc=ReadHoldingRegisters id=2070 change state Error -> None timestamp=63843421226 2024-05-13T10:18:08.444Z: Cmp=MODBUS lib, Class=1, Error=0, Info=0, pszInfo= ClientRequest,16#0164ADC561A0 unitId=1 fc=ReadHoldingRegisters id=2071 change state None -> Init timestamp=63844421420 2024-05-13T10:18:09.444Z: Cmp=MODBUS lib, Class=1, Error=0, Info=0, pszInfo= ClientRequest,16#0164ADC561A0 unitId=1 fc=ReadHoldingRegisters id=2071 change state Init -> Error timestamp=63845421675 But the errorID is jumping between OK and RequestNotProcessed. Any help is very appreciated which gives me a hint what I'm doing wrong. Thanks
Last updated: 2024-05-13

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