# Quantity=126,modbus-response , not recieve data

**URL:** <https://discourse.nodered.org/t/quantity-126-modbus-response-not-recieve-data/67457>\
**Category:** Industrial\
**Created:** [8 September 2022 01:56 UTC](https://discourse.nodered.org/t/quantity-126-modbus-response-not-recieve-data/67457 "2022-09-08T01:56:14Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![joe1](https://avatars.discourse-cdn.com/v4/letter/j/d26b3c/32.png) [@joe1](https://discourse.nodered.org/u/joe1)\
**Post date:** [8 September 2022 01:56 UTC](https://discourse.nodered.org/t/quantity-126-modbus-response-not-recieve-data/67457/1 "2022-09-08T01:56:14Z")

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Quantity=126,modbus-response , not recieve data  
I want to recive Quantity 200 length, but it does not work due to me not understanding how to use it effectively. Quantity=124 it working. why ?

work: 1-125  
not work: 126-x

 ![fc3-126quantity](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/c/1/c1f47e8ac3ec3e3d040c33751d9bc93d66e8aaca.jpeg)

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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:** [8 September 2022 02:19 UTC](https://discourse.nodered.org/t/quantity-126-modbus-response-not-recieve-data/67457/2 "2022-09-08T02:19:01Z")

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> [@joe1](#):
>
> Quantity=126,modbus-response , not recieve data

Its a limitation with the Modbus protocol ..  
the maximum amount of bytes that you can read in a single poll (256 bytes) ..  
this [article](https://control.com/forums/threads/maximum-amount-of-holding-registers-per-request.9904/#post-86251) explains better the byte calculations to derive to max 125 registers.

You can group your registers and do multiple sequential reads to gather all the data you need.

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [22 September 2022 02:19 UTC](https://discourse.nodered.org/t/quantity-126-modbus-response-not-recieve-data/67457/3 "2022-09-22T02:19:35Z")

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