# Modbus IO board help

**URL:** <https://discourse.nodered.org/t/modbus-io-board-help/81190>\
**Category:** General\
**Created:** [11 September 2023 09:22 UTC](https://discourse.nodered.org/t/modbus-io-board-help/81190 "2023-09-11T09:22:35Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![andre\_x](https://avatars.discourse-cdn.com/v4/letter/a/3d9bf3/32.png) [@andre\_x](https://discourse.nodered.org/u/andre_x)\
**Post date:** [11 September 2023 09:22 UTC](https://discourse.nodered.org/t/modbus-io-board-help/81190/1 "2023-09-11T09:22:35Z")

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Hi everybody!  
I have bought an [ethernet to RS485 board](https://it.aliexpress.com/item/1005004447630097.html?spm=a2g0o.order_detail.order_detail_item.7.6dfc582f3arHnz&gatewayAdapt=glo2ita) and an [IO board (8 in / 8 out)](https://it.aliexpress.com/item/1005005083867206.html?spm=a2g0o.order_detail.order_detail_item.5.6dfc582f3arHnz&gatewayAdapt=glo2ita).  
With the node _Modebus Read_ (node-red-contrib-modbus) I see that they communicate, but receive only zeros (In the input board the input 1 and 8 are high while the others are low).

 ![11-09-2023_11-18-10_6_Node-RED__192.168.0.28_—_Mozilla_Firefox](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/1/1/112072d02a9cf0789b15460c3644878c000777be.png)

The quantity that I can read is 48 (if I put 49, it doesn't read anything) and if I start over 0, it still doesn't read anything, so it seems that the registers are from 0 to 47.

Does anybody know how to read the input and to control the output?  
Thanks!

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [10 November 2023 09:23 UTC](https://discourse.nodered.org/t/modbus-io-board-help/81190/2 "2023-11-10T09:23:02Z")

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