# TCP-RTU Modbus Behaviour
**URL:** https://discourse.nodered.org/t/tcp-rtu-modbus-behaviour/99725
**Category:** General
**Created:** [20 November 2025 12:34 UTC](https://discourse.nodered.org/t/tcp-rtu-modbus-behaviour/99725 "2025-11-20T12:34:10Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Sido1](https://discourse.nodered.org/u/Sido1)
#### Post date: [20 November 2025 12:34 UTC](https://discourse.nodered.org/t/tcp-rtu-modbus-behaviour/99725/1 "2025-11-20T12:34:10Z")
I am experiencing inconsistent behavior with the Node-RED Modbus nodes when communicating with the same Modbus device.
When connecting through a TCP-RTU gateway:
Only the “Modbus-Read” node works
The “Modbus-Getter” node, which works perfectly when only reading the TCP, no longer works over TCP-RTU
The error message is: "Error: Timed out"
The warning: "Modbus Failure On State connected Get More About It By Logging"
TCP: Getter works, Flex-Getter fails
TCP-RTU: \*Only Read works, Getter and Flex-Getter fail
How is that possible?
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### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [18 February 2026 12:35 UTC](https://discourse.nodered.org/t/tcp-rtu-modbus-behaviour/99725/2 "2026-02-18T12:35:05Z")
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