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 egr99 on Modbus TCP Server connection is ESTABLISHED but all holding registers are value 0? ^{CODESYS Forge talk (Post)}
Hi there, Read the above description and experienced the same: Reading coil/discrete input/input register/holding register doesn't fill the mapped I/O variable. Any suggestions? Defined (see attachment): - Ethernet (with parameters according to the used Ethernet adapter of my Windows 11 laptop) - -Modbus TCP Client - - -LOGO231 as Modbus TCP Server - - -WS242 as Modbus TCP Server (WaveShare Modbus TCP <-> RTU converter) - - - -WS242_01 as Modbus Server, COM port (slave-id 1 RTU) - - - -WS242_03 idem (slave-id 3 RTU) - - - -WS242_11 idem (slave-id 11 RTU) Writing coil/holding register works from a mapped I/O variable works fine. Verification of Modbus traffic with WireShark: QUERY to and the RESPONSE of all slave-ids are correct Status of all defined is CONNECTED, RESPONSE_SUCCESS, RUNNING etc. Request counters increase with expected frequency. Error counter = 0. (To have all counters works fine I had to change Modbus TCP Client's parameter OptimizationON to FALSE). LOGO231 works fine: values in mapped I/O conform expectation WS242 without Modbus Server, COM port and with defined channels (for only 1 slave-id possible) works fine. PLC Settings: Update I/O while in stop: I see xBusy changing from FALSE to TRUE and vice versa. Always update variables: Enabled 1
Last updated: 4 days ago

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

Post by paulorb on STRUCT AT %MW1000 ^{CODESYS Forge talk (Post)}
Hi I am trying to use STRUCT to parse commands from Modbus/TCP, Modbus client will fill the bytes related to a specific command (type, parameters), then PLC (Codesys) will access the command parameters. A STRUCT will simplify a lot the process of parsing the data, so I don't need to parse byte per byte, address will be mapped to a struct and I can use it for parsing the data. From what I understood, the compiler does not allow me to specify the location of the struct for a %MW register. VAR_COMMAND AT %MW1002: structGenericModbusCommand; This will throw: Bad declaration, use '%ML' for 'structGenericModbusCommand' variable But If I change it to %ML, when you go online you see that it is actually allocating the struct in another memory address. When we go online, on GVL we can see: VAR_COMMAND. structGenericModbusCommand %ML1002 commandType COMMANDTYPE %MB8016 ... %MB8020 I am not specifying a pointer or a reference it is a struct type, why is it mapping to a %MW location (random one). How can I control where it is mapping to? I need a consistent way to map STRUCT to specific modbus address. Is it possible? Thanks, Paulo Note I am using a Codesys OEM: Schneider Machine Expert Logic Builder (M241)
Last updated: 2024-08-13

Post by laazik2 on v3.5 SP19 - Modbus TCP Devices - Channel Limit? ^{CODESYS Forge talk (Post)}
I am actually wondering as well if there are plans to fix it or not? As adding two modbus devices creates it's own problems with connection limits and other issues, which some slave devices have.
Last updated: 2023-09-05

How to use more 4 instances of CANopen/Profibus/Modbus with The application-based license CODESYS Control ^{CODESYS Forge talk (Thread)}
How to use more 4 instances of CANopen/Profibus/Modbus with The application-based license CODESYS Control
Last updated: 2023-11-02

Post by gorditron on Modbus Slave RTU in der Applikation abschalten ^{CODESYS Forge talk (Post)}
Hallo, gibt es eine Möglichkeit die Modbus Slaves (ModbusSlaveComPort) innerhalb der Applikation über ein Variable zu aktivieren oder zu deaktivieren? Bilder als Datei Danke!
Last updated: 2023-11-09

Post by brzozka100 on Change modbus server parameters from program ^{CODESYS Forge talk (Post)}
Hello, is there a possibility to change modbus server parameters (baud rate, parity, etc.) configured in devices tree from PRG? I need to be able to change them, for example, from HMI.
Last updated: 2024-07-16

Post by brzozka100 on Change modbus server parameters from program ^{CODESYS Forge talk (Post)}
Hello, is there a possibility to change modbus server parameters (baud rate, parity, etc.) configured in devices tree from PRG? I need to be able to change them, for example, from HMI.
Last updated: 2024-07-16

Post by wagomikep on Number of Connections to Modbus TCP Slave ^{CODESYS Forge talk (Post)}
Hello, Is there a maximum number of Masters that can connect to a Modbus Slave that is configured in the device tree? Is this limited by the CODESYS IDE, or the manufactures hardware and CPU load? Thank you,
Last updated: 2024-08-01

Post by wagomikep on Number of Connections to Modbus TCP Slave ^{CODESYS Forge talk (Post)}
Hello, Is there a maximum number of Masters that can connect to a Modbus Slave that is configured in the device tree? Is this limited by the CODESYS IDE, or the manufactures hardware and CPU load? Thank you,
Last updated: 2024-08-01

Post by wagomikep on Number of Connections to Modbus TCP Slave ^{CODESYS Forge talk (Post)}
Hello, Is there a maximum number of Masters that can connect to a Modbus Slave that is configured in the device tree? Is this limited by the CODESYS IDE, or the manufactures hardware and CPU load? Thank you,
Last updated: 2024-08-01

Post by wagomikep on Number of Connections to Modbus TCP Slave ^{CODESYS Forge talk (Post)}
Hello, Is there a maximum number of Masters that can connect to a Modbus TCP Slave that is configured in the device tree? Is this limited by the CODESYS IDE, or the manufactures hardware and CPU load? Thank you,
Last updated: 2024-08-01

Post by jacobwago on v3.5 SP19 - Modbus TCP Devices - Channel Limit? ^{CODESYS Forge talk (Post)}
Hello All, The solution is updating SP19 Modbus version from 4.3.0.0 to 4.4.0.0 (see attached image for bug fix). Thank you,
Last updated: 2024-09-30

Post by banialuk on Modbus TCP Server ^{CODESYS Forge talk (Post)}
I created Modbus Server TCP, but when I try started i have a error "TCP socet error" "Error on open/close/read/write TCP socket."
Last updated: 2024-10-21

Post by timvh on Modbus TCP & RTU with Control for Linux SL ^{CODESYS Forge talk (Post)}
Most likely your IP address is set to 172.... because you use a VPN connection to your device. Probably best to use the other Ethernet interface for your modbus communication.
Last updated: 2024-10-24

Post by gatto on Application-based license Modbus Channels ^{CODESYS Forge talk (Post)}
Hi Sandro, did you find any solution? I'm in version 3.5.20.40 and i have only one modbus channel. I don't want the problem to happen to me if I do an update one day.
Last updated: 2025-09-01

Post by cmason on v3.5 SP19 - Modbus TCP Devices - Channel Limit? ^{CODESYS Forge talk (Post)}
There still is no solution to this. I am running Modbus version 4.4.0.0 and it still wont let me add more than 10 channels. Does anyone have a solution for this?
Last updated: 2025-09-05

Post by cmason on v3.5 SP19 - Modbus TCP Devices - Channel Limit? ^{CODESYS Forge talk (Post)}
There still is no solution to this. I am running Modbus version 4.4.0.0 and it still wont let me add more than 10 channels. Does anyone have a solution for this?
Last updated: 2025-09-05

Controlling PM564-eth PLC using Weintek HMI with MODBUS TCP/I. I keep getting communication errors. ^{CODESYS Forge talk (Thread)}
Controlling PM564-eth PLC using Weintek HMI with MODBUS TCP/I. I keep getting communication errors.
Last updated: 2021-02-15

Post by squiggleypuff on Can't Add New Version of Modbus TCP Master ^{CODESYS Forge talk (Post)}
Turns out Modbus was working despite the pre-compiler errors; I was reading the wrong addresses of the slave device, which was why I was seeing all 0s. Thanks for ignoring me.
Last updated: 2024-04-09

Post by tobifenny on Modbus TLS Kommunikation ^{CODESYS Forge talk (Post)}
Hier ist das handbuch: https://www.kostal-solar-electric.com/fileadmin/downloadcenter/kse/BA_KOSTAL_Interface_KSEM_DE.pdf Im Kapitel 1.3.2 ist das mit dem TLS beschrieben und in Kapitel 3.6.2 sind die Modbus-Register beschrieben.
Last updated: 2025-11-06

Post by ggaida on runtime dynamic modbus devices ^{CODESYS Forge talk (Post)}
Kurtk, I am working through a very similar scenario. I am curious if you have had any success since your post in implementing dynamic modbus configurations? Thx!
Last updated: 2025-11-20

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