Post by itsthefabs on (no subject) ^{CODESYS Forge talk (Post)}
Hallo zusammen, ich nutze eine Wago 8212 als Modbus Client (in früheren Codesys Versionen hieß der Modbus Master) und habe einen weitere Wago 8212 als Modbus Server (früher Modbus Slave). Bisher habe ich für den Client den Funktionsblock FbMbMasterTcp aus der WagoAppPlcModbus-Library genutzt. Zukünftig würde ich das allerdings gerne über das Anhängen eines Modbus-Geräts am Ethernet-Knoten im Projektbaum realisieren. Zum besseren Verständnis habe ich ein Bild beigefügt. Der Modbus mit dem Server läuft auch. Kommt es allerdings zum Fehler des Modbus, z.B. kurzzeitig keine Verbindung oder timeout, wird der Fehler nicht automatisch quittiert. Ich muss dann manuell über den Status des Server-Knotens einen Button mit "Bestätigen" drücken. Im Betrieb kann ich mich aber nicht jedes Mal einloggen um einen Fehler zu quittieren. Gibt es hier irgend einen Trick, wie ich das aus dem Programm-Code quittieren kann? Vielen Dank schon einmal.
Last updated: 2025-02-26

Post by ben1 on How to write multiple coils (Modbus FC15) ^{CODESYS Forge talk (Post)}
When you say it does not work, does nothing happen or do you get an error? I have not used this function in codesys but from my past experience with Modbus I believe the coils need to be contiguous, which may be why yours is failing? Have you tried using Write Registers (16) to do the job? Or is their data in-between you do not want to edit in the transaction?
Last updated: 2024-11-17

Post by wind-11 on Problem with simulation Modbus ^{CODESYS Forge talk (Post)}
Hello everyone, I encountered a problem in the simulation while working. In a test project we set up a Modbus connection. We wanted to simulate this with test values. The connection also worked, but unfortunately the values are frozen and do not report any “current data”. (Picture attached) Since these are my first points of contact with Codesys and my colleague continues to work elsewhere, I was hoping that someone here might have an idea. Kind regards and thanks in advance.
Last updated: 2024-03-22

Post by uluking on CodeSys2.3 Modbus 64-Bit Double Read Problem ^{CODESYS Forge talk (Post)}
Hi everyone, I would appreciate your help with a problem I've been working on for a few days but haven't been able to resolve. I am reading data from a Siemens PAC3220 energy analyzer using Modbus with Wago-8202. However, the device's energy indices are given as doubles. Since a double variable is 64-bit, it is not possible to read it directly. I have been struggling for days, I have written many conversion functions but I have not been able to get results. I would appreciate your help. I read 4 word variables and processed them. I am converting them according to IEEE-754, but I can't seem to read the correct data. I would appreciate your help.
Last updated: 2025-10-27

Post by uluking on CodeSys2.3 Modbus 64-Bit Double Read Problem ^{CODESYS Forge talk (Post)}
Hi everyone, I would appreciate your help with a problem I've been working on for a few days but haven't been able to resolve. I am reading data from a Siemens PAC3220 energy analyzer using Modbus with Wago-8202. However, the device's energy indices are given as doubles. Since a double variable is 64-bit, it is not possible to read it directly. I have been struggling for days, I have written many conversion functions but I have not been able to get results. I would appreciate your help. I read 4 word variables and processed them. I am converting them according to IEEE-754, but I can't seem to read the correct data. I would appreciate your help.
Last updated: 2025-10-27

Post by struccc on Problem Reading Registers via Modbus from non Codesys device ^{CODESYS Forge talk (Post)}
Hi, Might be a good idea first to try out the connection and the device with some handy software, like Modbus Poll. There you can see better, what's really going on... - Is it really connected? - What error code does it return? - Can it read from the register address? - Maybe try Input registers and Holding Registers - can make a difference - Sometimes register addresses are messed up: shifted +-1 (mixing of 2 standards) - Sometimes register addresses start with offset 30000, 40000 ... - Are you using the right protocol? - Is it RTU or TCP? Maybe ASCII? - Can even have a look at the data packets, etc... All this is easier to figure out first with some modbus utility... and then to set it up in CODESYS should not be an issue. P.
Last updated: 2025-03-09

Post by mbmik on IoDrvModbusTCP_Diag not defined when using MODBUS ^{CODESYS Forge talk (Post)}
Hi Im trying to setup a Weidmüller WL2000 to run with MODBUS, to get some data from a server. Codesys V3.5 SP20. The issue is, that whenever i attach an ethernet port and add MODBUS Master und also a Slave, codesys will compile the project, but there always seem to be some remaining errors, which or only visible, when setting the messages window to "Pre-Compiled". I tried a lot of stuff to get rid of these errors, but cant find to seem the reason. New installation of codesys, cleaned project, setup completely empty new project, manually adding libs. Nothing helps. Any help is apreciated. Maybe we are doing something wrong.. Example Project is available, if somebodey wants to take a look. Greetings and thanks alot
Last updated: 2024-04-15

Post by schorge on Modbus RTU Slave ^{CODESYS Forge talk (Post)}
Ich würde gerne bestimmt Modbus RTU Slave Adressen auslesen, leider bekomme ich keine Werte vom Bus. Verbindung erfolgt über einen Raspberry mit Modbus RS485 Adapter, welcher erfolgreich verbunden ist. Mit einem IOBroker kann ich die Daten erfolgreich auslesen. In der Modbus_COM_Port => Modbus_Serial_Device habe ich Input Register 4000 %QW und Startadressen auf Input Register 3000, als Variable ein Array[0..2999] of Word, kann aber keine Werte auslesen.
Last updated: 2023-12-06

Post by dengsberg on Disable Communications to 'Modbus_Server_COM_Port' from the logic ^{CODESYS Forge talk (Post)}
I have a serial Modbus RTU communicating to the Slave device. But when the control system is not in Run there is no power applied to one of the Modbus Devices. Can I enable / disable the communications to that Modbus Slave in the code based on my running mode, so I don't get all the errors?
Last updated: 2024-08-29

Post by bolopg on MODBUS TCP REGISTERS CODESYS V3.5 ^{CODESYS Forge talk (Post)}
Hi. I have a problem with MODBUS TCP MASTER. I treid to read HR in range 3027-3037 but I cannot read them. I have modbus slave chanel with offset 0x3037. I checked what I read and it looks like I am reading HR in range 1-10. What I am doing wrong.
Last updated: 2024-10-11

Post by wbj0t on one variable signed to modbus tcp server device and modbus serial device ^{CODESYS Forge talk (Post)}
Hi. Raspberry pi 4 runtime. Runtime version 4.16, IDE version 3.5.21. Is it possible write new value for variable via modbus tcp or serial devices when both enabled? As I see - not. What can I do? It is terrible restriction.
Last updated: 2025-07-17

Post by hinet on 22kW Wallbox mit Modbus ^{CODESYS Forge talk (Post)}
Hallo an alle, ich schaue mir gerade ein paar 22kW Wallboxen an: https://shop.einfacheauto.de/collections/22-kw-wallboxen Mir wäre vor allem wichtig, dass die Kommunikation per Modbus gut funktioniert. Es werden zwar ein paar Wallboxen gelistet, die Modbus ermöglichen, trotzdem wollte ich euch nach Erfahrungen fragen, welche Modelle in der Hinsicht besonders problemfrei funktionieren.
Last updated: 2025-11-06

Post by ahuckphin on Issues with Modbus Slave with Raspberry Pi ^{CODESYS Forge talk (Post)}
I have a DFRobot RS485 temperature & humidity sensor (SEN0438) connected to my Raspberry Pi via a USB to RS485 adapter. I am able to connect and read the sensor data when running a python code locally. However in Codesys, I encounter this error "A bus error has occurred." and "There was no response in time". Could this be because of Modbus Server Channel and Modbus Server Init configuration on my part? Admittedly I am new to Codesys. To get to this stage, I: 1. added some lines to CODESYSControl_User.cfg 2. added "Modbus_COM" in Codesys and set "Serial Port Configuration" under "General" 3. added "Modbus_Master_COM_Port" in Codesys and checked transmission mode is set to "RTU" 4. added "Modbus_Slave_COM_Port" in Codesys and checked server address is set to 1 (also set 1 in my sensor) 5. added 1 channel and 1 init for "Modbus_Slave_COM_Port" under "Modbus Server Channel" and "Modbus Server Init"
Last updated: 2024-07-10

Post by timvh on Accessing ModbusTCP addresses from python ^{CODESYS Forge talk (Post)}
https://en.wikipedia.org/wiki/Modbus
Last updated: 2023-09-20

Post by ahuckphin on Issues with Modbus Slave with Raspberry Pi ^{CODESYS Forge talk (Post)}
duplicate
Last updated: 2024-07-11

Post by dohy on Modbus RTU Response CRC fail ^{CODESYS Forge talk (Post)}
Did you resolve it?
Last updated: 2024-09-19

Post by ph0010421 on MODBUS TCP REGISTERS CODESYS V3.5 ^{CODESYS Forge talk (Post)}
hello Use FC3 instead of FC4
Last updated: 2024-10-11

Post by bartspako on Connection between Beijer PLC and Schneider Tesys-Island using Modbus TCP ^{CODESYS Forge talk (Post)}
Last updated: 2024-10-16

Post by dkugler on STRING size and reading STRING with Modbus ^{CODESYS Forge talk (Post)}
Last updated: 2025-01-31

Post by sandro66 on Application-based license Modbus Channels ^{CODESYS Forge talk (Post)}
Hi Gatto, Using version 3.5.21.xx, it is no longer possible to use Modbus function blocks (I make extensive use of these FBs.)as shown in the example. https://content.helpme-codesys.com/en/CODESYS%20Examples/_ex_modbus_example.html The compiler detects one Modbus instance for each instance of the communication FB block. The example program above, although simple, reports 8 Modbus instances when compiled with the latest version. Codesys Support says that you must use fieldbus I/O mapping, but this will result in the loss of the ability to programmatically modify communication parameters. Sandro
Last updated: 2025-09-04

Post by eschwellinger on IoDrvModbusTCP_Diag not defined when using MODBUS ^{CODESYS Forge talk (Post)}
known issue hopefully solved to next version
Last updated: 2024-04-18

Post by tobifenny on Modbus TLS Kommunikation ^{CODESYS Forge talk (Post)}
Ich habe eine Wallbox, die ich gerne per Modbus ansteuern würde. Die Normale Modbus-Kommunikation, um ein paar Werte auszulesen klappt auch. Wenn ich aber Zugriff auf bestimmte Modbus-Register haben möchte, benötigt die Wallbox ein TLS-Zertifikat. Das Zertifikat habe ich bereits erstellt und im Security-Sreen unter Eigene Zertifikate hochgeladen. Weiter komme ich aber nicht mehr. Wie baue ich eine TLS-Verbindung mit der Waalbox auf? Vielleicht hat das ja schonmal jemand gemacht und ein Beispiel für mich. Ich bin über jede Hilfe sehr Dankbar!
Last updated: 2025-11-05

Post by milan-svarny on ModbusFB.ClientSerial Problem with Reply Timeout ^{CODESYS Forge talk (Post)}
Hi All, I have problem with ModbusFB.ClientSerial. I'm using 4 different port for Modbus communication. After some time of running program ClientSerial stops to receive data to reply buffer and all request finish with Reply Timeout. The Device sent reply correctly,that it is visible on oscilloscope and it is possible to see that data( reply )are in the device. If the usbtty device is read over external app. then it is possible to see all data which were not taken by ModbusFB.ClientSerial. The stack does not overflow or something , program runs correctly forward and no exceptions or something. The main problem it is that when the error occur than it is not possible to reset port or something or maybe i'm doing it wrong way. please help me with this issue. Thank you for any help in advice Milan
Last updated: 2025-05-23

Post by sumit on Not able to see input data coming from eip adapter on codesys ^{CODESYS Forge talk (Post)}
Hello there, I have an eip adapter running (remotely) that is sending data back to eip scanner (running on codesys). I can send data from scanner (codesys) to the adapter but not getting the data back from the adapter. I have verified the incoming data on wireshark but I don't see this data in the codesys. I have tried local variable mapping and global variable mapping not variable values just stays at 0. Please guide.
Last updated: 2024-02-29

Hi, I try to send and receive data using a UDP connection via SysSocket 3.5.17.0. While sending data works fine, I have problems with the receiving part. I am able to capture the received data of client side in wireshark But unable to capture it on the codesys ^{CODESYS Forge talk (Thread)}
Hi, I try to send and receive data using a UDP connection via SysSocket 3.5.17.0. While sending data works fine, I have problems with the receiving part. I am able to capture the received data of client side in wireshark But unable to capture it on the codesys
Last updated: 2024-06-03

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