MQTT, TCP Socket Client ^{CODESYS Forge talk (Thread)}
MQTT, TCP Socket Client
Last updated: 2023-04-02

TCP Socket example? ^{CODESYS Forge talk (Thread)}
TCP Socket example?
Last updated: 2018-01-29

Two tcp ^{CODESYS Forge talk (Thread)}
Two tcp
Last updated: 2017-12-23

Communication on TCP ^{CODESYS Forge talk (Thread)}
Communication on TCP
Last updated: 2014-04-03

Daten Übertragung TCP/ip ^{CODESYS Forge talk (Thread)}
Daten Übertragung TCP/ip
Last updated: 2008-09-17

Using TCP Client ^{CODESYS Forge talk (Thread)}
Using TCP Client
Last updated: 2017-07-04

TCP-IP Port öffnen ^{CODESYS Forge talk (Thread)}
TCP-IP Port öffnen
Last updated: 2011-08-23

Library 'TCP' ^{CODESYS Forge talk (Thread)}
Library 'TCP'
Last updated: 2019-06-21

TCP/IP example ^{CODESYS Forge talk (Thread)}
TCP/IP example
Last updated: 2014-05-25

TCP / IP Kommunikation ^{CODESYS Forge talk (Thread)}
TCP / IP Kommunikation
Last updated: 2009-08-19

TCP/IP client ^{CODESYS Forge talk (Thread)}
TCP/IP client
Last updated: 2023-12-20

Modbus: dis- / re-connect cable: modbus does not re-start ^{CODESYS Forge talk (Thread)}
Modbus: dis- / re-connect cable: modbus does not re-start
Last updated: 2013-09-28

new to codesys help on modbus with ardunio modbus rtu ^{CODESYS Forge talk (Thread)}
new to codesys help on modbus with ardunio modbus rtu
Last updated: 2024-07-21

Modbus : dis- / re-connect cable: modbus does not re-start ^{CODESYS Forge talk (Thread)}
Modbus : dis- / re-connect cable: modbus does not re-start
Last updated: 2025-03-18

Codesys 2.3 OPC Server auf Windows Server 2012 R2 Standard ^{CODESYS Forge talk (Thread)}
Codesys 2.3 OPC Server auf Windows Server 2012 R2 Standard
Last updated: 2016-02-03

WIN 2008 Server - OPC Server CodeSys - HELP ^{CODESYS Forge talk (Thread)}
WIN 2008 Server - OPC Server CodeSys - HELP
Last updated: 2010-11-17

Post by mil581 on Modbus TCP Server connection is ESTABLISHED but all holding registers are value 0? ^{CODESYS Forge talk (Post)}
Hello everyone! I'm facing a weird issue with CODESYS Control Win V3 x64 on a fresh Windows install. The situation is as follows: CODESYS Modbus TCP Server (Slave) is running and I can see live values in the mapping display of Modbus settings: GVL (e.g., 32, 42, 50). Port 502 is LISTENING according to netstat. When connecting via Modbus Poll or Node-RED, the connection status changes to ESTABLISHED and everything reports as fine. The Problem: Despite the successful connection, all holding registers return 0 no matter what. It's like the OS accepts the TCP handshake, the request counter goes up but the data payload never reaches Modbus Client (in this case Node-RED or Modbus Poll). Quick Stats: Firewall: Completely OFF. Unit ID: Verified & Matching. IP: Tried 127.0.0.1 and 192.168.0.1. Interface: Correctly bound in Ethernet Device settings. I already tried absolutely everything from changing IP address, subnet, port, deleting the project and starting new one and even nuking my old Windows install. Since I am near completion of my bachelor thesis only thing left for me to do is connect SoftPLC to NodeRED via Modbus but this issue is driving me crazy for weeks. I do not know what to do anymore.
Last updated: 2 days ago

Post by fmon on Modbus : dis- / re-connect cable: modbus does not re-start ^{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" 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 reconnection. What is different at the first connection and at a reconnection attempt ? Thanks for your help
Last updated: 2025-03-14

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

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 kurtk on Modbus TCP Server ^{CODESYS Forge talk (Post)}
ditto I'm just getting my codesys wheels on and the modbus stuff is confusing. I am re-platforming an existing PLC application On that platform one could simply tag variables to register numbers and the whole shooting match could be accessed via modbus and typically holding registers and input registers were treated the same way... On codesys I see there is a modbus TCP server Device I/O mapping tab and a Modbus TCP server IEC objects tab I get the sense that one can configure the serving of variables both/either way but am unclear about the optimum/necessary path. Apparently in the IEC Objects tab one can "ADD" something or other - presumeably channels. I have created a preliminary function block but the Select Function Block window shows nothing to select WTH ? I exported the Device mapping and was surprised to see the entire Device IO map - complete with all the bit-mapped holding/input registers!! WTH!!?? Bit-mapped words are strictly a nichey special purpose application. I am targetting making a couple hundred variables available which would turn into hundreds of pages of IO/mapping Is the FUnction Block IEC objects thingy an alternative to that ? I notice that CODESYS shows the tags which the PLC used to specify the register address... are tags used in CODESYS for any specific hard-core purpose ?
Last updated: 2025-08-19

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

Modbus Extended Registers ^{CODESYS Forge talk (Thread)}
Modbus Extended Registers
Last updated: 2023-08-26

Modbus RTU 485 ^{CODESYS Forge talk (Thread)}
Modbus RTU 485
Last updated: 2020-02-02

Modbus RTU Library Enquiry ^{CODESYS Forge talk (Thread)}
Modbus RTU Library Enquiry
Last updated: 2021-07-29

Sort by relevance or date