# Data not write in modbus

**URL:** <https://discourse.nodered.org/t/data-not-write-in-modbus/84482>\
**Category:** General\
**Created:** [11 January 2024 14:55 UTC](https://discourse.nodered.org/t/data-not-write-in-modbus/84482 "2024-01-11T14:55:13Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![PRABHAKAR82](https://avatars.discourse-cdn.com/v4/letter/p/e47c2d/32.png) [@PRABHAKAR82](https://discourse.nodered.org/u/PRABHAKAR82)\
**Post date:** [11 January 2024 14:55 UTC](https://discourse.nodered.org/t/data-not-write-in-modbus/84482/1 "2024-01-11T14:55:13Z")

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[flows (3).json](https://discourse.nodered.org/uploads/short-url/i3lxC0vI5ghx5kq5YQ8HS2Vj5c1.json) (7.7 KB)

Please see my attached flow and guide where I did mistake.

When I write data into Modbus server through inject node then it write on Modbus server,  
But when I try to write data of MQTT then its not write on Modbus.  
Both have same output Format(msg.payload : array[51])

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**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [11 January 2024 15:12 UTC](https://discourse.nodered.org/t/data-not-write-in-modbus/84482/2 "2024-01-11T15:12:46Z")

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Add a debug mode showing what you are sending to the server node. Click the inject node and then trigger the mqtt input and show us what you see for each case.

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**Author:** ![PRABHAKAR82](https://avatars.discourse-cdn.com/v4/letter/p/e47c2d/32.png) [@PRABHAKAR82](https://discourse.nodered.org/u/PRABHAKAR82)\
**Post date:** [11 January 2024 15:55 UTC](https://discourse.nodered.org/t/data-not-write-in-modbus/84482/3 "2024-01-11T15:55:11Z")

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![mod](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/1/0/1084d0b43ad2ac5db1330637effd414f4f723f1a.png)  
 ![modus](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/6/1/61ddff7b77bcf60d7257f845d9bad9f592d08b06.png)  
 ![modus_d](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/0/b/0b1b2d51f862d9c8a702db5d4da924ad6470db8a.png)

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**Author:** ![PRABHAKAR82](https://avatars.discourse-cdn.com/v4/letter/p/e47c2d/32.png) [@PRABHAKAR82](https://discourse.nodered.org/u/PRABHAKAR82)\
**Post date:** [11 January 2024 15:56 UTC](https://discourse.nodered.org/t/data-not-write-in-modbus/84482/4 "2024-01-11T15:56:26Z")

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both have same data format

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**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [11 January 2024 16:05 UTC](https://discourse.nodered.org/t/data-not-write-in-modbus/84482/5 "2024-01-11T16:05:12Z")

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Yes, but `debug 307` has completely different values!

All Modus data is 16 bit & therefore 65535 is the MAX value permissible

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**Author:** ![PRABHAKAR82](https://avatars.discourse-cdn.com/v4/letter/p/e47c2d/32.png) [@PRABHAKAR82](https://discourse.nodered.org/u/PRABHAKAR82)\
**Post date:** [11 January 2024 16:25 UTC](https://discourse.nodered.org/t/data-not-write-in-modbus/84482/6 "2024-01-11T16:25:34Z")

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yes got it thanks.

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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:** [25 January 2024 16:25 UTC](https://discourse.nodered.org/t/data-not-write-in-modbus/84482/7 "2024-01-25T16:25:48Z")

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