# MODBUS connection problems

**URL:** https://discourse.nodered.org/t/modbus-connection-problems/51786
**Category:** General
**Created:** [3 October 2021 01:33 UTC](https://discourse.nodered.org/t/modbus-connection-problems/51786 "2021-10-03T01:33:34Z")
**Posts on this page:** 1
**Showing post:** 4

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### Author: ![UnborN](https://avatars.discourse-cdn.com/v4/letter/u/4491bb/32.png) [@UnborN](https://discourse.nodered.org/u/UnborN)
#### Post date: [3 October 2021 12:05 UTC](https://discourse.nodered.org/t/modbus-connection-problems/51786/4 "2021-10-03T12:05:26Z")

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Hello .. you can follow the recommendations in this [thread](https://discourse.nodered.org/t/serial-port-rs485-question/37817/2)  
that a similar RPi Hat is being used.

```plaintext
sudo raspi-config
goto '5 Interfacing Options'
goto 'P6 Serial'
'Would you like a login shell to be accessible over serial?' --> NO
'Would you like the serial port hardware to be enabled?' --> YES
Finish raspi-config
reboot the Raspberry Pi

```

> [@blunoz](#):
>
> I can read the device registers fine with a USB dongle and Windows

as a test. Can you read with the USB to RS485 dongle on the RPi ? (instead of Windows)

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