Ethernet (TCP/IP) ^{CODESYS Forge talk (Thread)}
Ethernet (TCP/IP)
Last updated: 2022-06-02

Kommunikation über TCP-IP ^{CODESYS Forge talk (Thread)}
Kommunikation über TCP-IP
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TCP Socket communication ^{CODESYS Forge talk (Thread)}
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Last updated: 2006-02-09

raspberry tcp socket ^{CODESYS Forge talk (Thread)}
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Last updated: 2018-01-30

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

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Last updated: 2017-12-23

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Last updated: 2014-04-03

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Using TCP Client
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TCP-IP Port öffnen ^{CODESYS Forge talk (Thread)}
TCP-IP Port öffnen
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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

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TCP / IP Kommunikation
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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: 2025-12-25

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