Post by fedu on Programmatically change the IP addresses of the Modbus TCP slave devices ^{CODESYS Forge talk (Post)}
I have the same need. Did you solve it? thanks
Last updated: 2024-12-10

Post by timvh on Problem Reading Registers via Modbus from non Codesys device ^{CODESYS Forge talk (Post)}
According to the documentation: https://wiki.teltonika-networks.com/view/RUT956_Modbus You need to create a Channel to read 2 registers from address 143 to get the lattitude. It doesn't specify if you need to read it as a Holding Register or as an Input Register. You could try both. So in the Teltonika router, you need to enable it as being a Modbus Server. Then in CODESYS add an Ethernet Adapter, then a Modbus Client (Master) and to the Client (Master) add the Modbus Server (Slave). Set the IP address and add the Channel. The please consider that CODESYS doesn't update any variables when they are not used in the application. In the I/O mapping tab of your I/O configuration, you can set the "Always update" to enabled.
Last updated: 2025-03-08

Post by zdenekkrejci on Issues with Modbus Slave with Raspberry Pi ^{CODESYS Forge talk (Post)}
Did you find out what was wrong? I have the same issue
Last updated: 2025-03-09

Post by zdenekkrejci on Issues with Modbus Slave with Raspberry Pi ^{CODESYS Forge talk (Post)}
Did you find out what was wrong? I have the same issue
Last updated: 2025-03-09

Post by nz-dave on Modbus TCP/IP having problems with global variables ^{CODESYS Forge talk (Post)}
IN THE MAPPING COLUMN, TRY CLICKING THE ICON TO "MAP TO EXISTING VAR"
Last updated: 2025-05-21

Post by eschwellinger on ModbusTCP RaspberryPi zu Fronius Wechselrichter ^{CODESYS Forge talk (Post)}
Schreibe den Slavename(der vom Gerätebaum) in ein Watchfenster dann siehst du Instanz des Modbus Slave Fb's und hast dadurch Diagnose Info
Last updated: 2025-07-04

Post by eschwellinger on Application based license problem - Modbus TCP ^{CODESYS Forge talk (Post)}
Which versions exactly are involved? Runtime on PI? CODESYS Version and compilerversion?
Last updated: 2023-12-18

Post by eschwellinger on Application based license problem - Modbus TCP ^{CODESYS Forge talk (Post)}
you could sent the projectarchive to 'my question' in the CODESYS store
Last updated: 2023-12-18

Post by solidlogicguy on Little endian to Float from Modbus RTU ^{CODESYS Forge talk (Post)}
Just tried and returns the same value but in scientific notation.
Last updated: 2024-01-08

Post by bfunk on Wago 750-8101 (mit Codesys V3) als Profinet device ^{CODESYS Forge talk (Post)}
Moin, ich habe da ein Problem und komme einfach nicht weiter... Ich moechte eine Wago 750-8101 (mit Codesys V3) zu einem ModBus TCP Slave und einem Profinet slave machen. ModBus habe ich hinbekommen, Profinet bekomme ich einfach nicht hin. habt ihr das evtl. einen hilfreichen Tip fuer mich? Programmiert wird mit Codesys V3.5 SP19 Patch 2 Auf dem Zielsystem (PFC100) ist die Zielsystemversion 4.6.0.0 Das es nicht optimal ist PN und ModBus TCP auf einer Schnittstelle zu haben ist mir bewusst. Wollte aber erstmal ModBus und Profinet zum laufen bekommen bevor ich das Profinet auf die 2. Ethernet-Schnittstelle bringe. /etc/CODESYSControl_User.cfg [SysSocket] Adapter.0.Name="br0" Adapter.0.EnableSetIpAndMask=1 Adapter.1.Name="br1" Adapter.1.EnableSetIpAndMask=1 ist eingetragen. so sieht der Status fuer das PN-device aus. Anbei ein Screenshot.
Last updated: 2024-01-16

Post by jbarrio on v3.5 SP19 - Modbus TCP Devices - Channel Limit? ^{CODESYS Forge talk (Post)}
Also, this solution is not valid for the RTU, I imagine that this bug should be a high priority...
Last updated: 2024-01-22

Post by rh-pk on v3.5 SP19 - Modbus TCP Devices - Channel Limit? ^{CODESYS Forge talk (Post)}
Hi, i found a solution for me. I had installed a 'old' version of CoDeSys (3.5.18 P5). I tried to add channels there, which works fine. I created a new project, added an Ethernet-Port, added a Modbus-Master and then I copied the ModBus-Slave from my working project to the new project. Now I could add more channels. I add the channels 10 and 11. Then I deleted (please make a backup before :-) the original ModBus-Slave in my working project and copied the extended Slave back to my working project. Surprisingly it is now possible to add new channels. Maybe this will help you.
Last updated: 2024-02-14

Post by tokamk on Dynamic setting of the modbus tcp/ip slave ip address ^{CODESYS Forge talk (Post)}
Hello, I'm working on a project which includes Panel-PC which communicates with a PLC through Modbus TCP/IP. On the PLC I have a CODESYS code which has Modbus slave objects. The Modbus slave objects have to have manually set IP address in order for them to work properly and the Ip address has to be the PC-Panels's IP. This project is going to a customer and they're using their own IP address realm. So, my question is that is it possible to configure these slaves in some other way, so that the customer doesn't need to modify the CODESYS project? I was thinking that would it be possible to set the IP address of these slaves from external source?
Last updated: 2024-02-15

Post by tomast on Siemens V20 Frequenzumrichter über Modbus RTU ^{CODESYS Forge talk (Post)}
Hi Tim, Have you sorted out your problem because i have also problems with i?
Last updated: 2024-03-21

Post by dawidr on Timeout Error in Modbus Communication with WAGO PFC200 and iEM2050 Meter using 750-652 Module ^{CODESYS Forge talk (Post)}
Last updated: 2024-04-07

Post by csanderson on IoDrvModbusTCP_Diag not defined when using MODBUS ^{CODESYS Forge talk (Post)}
I am also having this same issue after upgrading to 3.5.20.0. Any help Codesys?
Last updated: 2024-04-17

Post by santana on IoDrvModbusTCP_Diag not defined when using MODBUS ^{CODESYS Forge talk (Post)}
I'm having this same issue. I upgraded to 3.5.20.0 from 3.5.19.20. Now I have the precompile errors shown above.
Last updated: 2024-04-17

Post by eschwellinger on IoDrvModbusTCP_Diag not defined when using MODBUS ^{CODESYS Forge talk (Post)}
error need to be solved by CODESYS. hopefully next release
Last updated: 2024-05-01

Post by zer0g on Modbus Client Request Not Processed ^{CODESYS Forge talk (Post)}
Hi, Thank you for your suggestion but the problem is fixed after I disabled and enabled the network adapter from Windows settings.
Last updated: 2024-05-30

Post by eschwellinger on Modbus TLS Kommunikation ^{CODESYS Forge talk (Post)}
hi, das geht leider nicht mit aktivierter Verschlüsselung , sorry - denke aktuell bleibt dir nur auf Slave Seite die Verschlüsselung zu deaktivieren.
Last updated: 2025-11-09

Post by ahuckphin on Issues with Modbus Slave with Raspberry Pi ^{CODESYS Forge talk (Post)}
codesyscontrol_user.cfg [SysCom] Linux.Devicefile.1 = /dev/ttyUSB0 portnum:=COM.SysCom.SYS_COMPORT1; **parameters are used in the python-script ** method: "rtu" port: "COM8" baudrate: 9600 stopbits: 1 bytesize: 8 parity: 'N' timeout: 1 register address for humidity: 0x000 register address for temperature: 0x001 unit ID: 1 **parameteized in the modbus-master-comport ** see attached files
Last updated: 2024-07-11

Post by nltheves on Raspberry PI4 Serial Port ^{CODESYS Forge talk (Post)}
Hi Ricardo. I was having the same problem with Codesys and a Raspberry Pi 2W while using the GPIO uart. Your post helped me a lot. Thanks! But could not understand why MODBUS parity bit makes Codesys MODBUS COM driver stopping to work after first request transmission. Did you see this @eschwellinger ? Regards, Nelson
Last updated: 2024-07-18

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

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