# Node-red-contrib-modbus, problem with modbus serie

**URL:** <https://discourse.nodered.org/t/node-red-contrib-modbus-problem-with-modbus-serie/83038>\
**Category:** General\
**Created:** [20 November 2023 16:13 UTC](https://discourse.nodered.org/t/node-red-contrib-modbus-problem-with-modbus-serie/83038 "2023-11-20T16:13:42Z")\
**Posts on this page:** 5\
**Page:** 2

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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:** [5 December 2023 13:25 UTC](https://discourse.nodered.org/t/node-red-contrib-modbus-problem-with-modbus-serie/83038/21 "2023-12-05T13:25:45Z")

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Can you repeat the test but first stop Node-red and start it again by using the command  
`DEBUG=contribModbus* node-red -v`

This will tell the Modbus nodes to print a more detailed step-by-step log of every action in the Terminal  
Maybe this can give some clues of what is happening ([DEBUG](https://github.com/BiancoRoyal/node-red-contrib-modbus/wiki/DEBUG))

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**Author:** ![T3NCHU4N](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/t3nchu4n/32/82773_2.png) [@T3NCHU4N](https://discourse.nodered.org/u/T3NCHU4N)\
**Post date:** [5 December 2023 23:41 UTC](https://discourse.nodered.org/t/node-red-contrib-modbus-problem-with-modbus-serie/83038/22 "2023-12-05T23:41:02Z")

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Dear Unborn, thank you for your contribution, it seems that the nodes miscalculate the CRC, here is the screenshot of the error reading 14 records in a message:

contribModbus:queue:core queue serial lock command node name: undefined id: 2b558b491bee4c8a +3s  
contribModbus:queue:core sequential de-queue command +2ms  
contribModbus:queue:core queue serial unlock command node name: undefined id: 2b558b491bee4c8a +41ms  
contribModbus:queue:core queue serial unlock command node name: undefined id: 2b558b491bee4c8a +2ms  
contribModbus:flex:getter CRC error +3s  
contribModbus:basics CRC error +3s

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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:** [6 December 2023 00:10 UTC](https://discourse.nodered.org/t/node-red-contrib-modbus-problem-with-modbus-serie/83038/23 "2023-12-06T00:10:05Z")

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> [@T3NCHU4N](#):
>
> CRC error +3s

Maybe this issue from the modbus Node's Github page is related to your problem.  
[Unable to read more than 10 - 12 addresses with Modbus Read / Modbus Flex Read when using RTU #239](https://github.com/BiancoRoyal/node-red-contrib-modbus/issues/239)

There its mentioned that what worked for them is using RTU-BUFFERED instead of RTU in the modbus client configuration.

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<div class="post-metadata">

**Author:** ![T3NCHU4N](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/t3nchu4n/32/82773_2.png) [@T3NCHU4N](https://discourse.nodered.org/u/T3NCHU4N)\
**Post date:** [6 December 2023 00:36 UTC](https://discourse.nodered.org/t/node-red-contrib-modbus-problem-with-modbus-serie/83038/24 "2023-12-06T00:36:28Z")

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Dear Unborn, that has been the problem, I have tested it and it works perfectly, reading as RTU BUFFERED. I thank you for helping me and I apologize for not having found the solution on github on my own, it seems like I have hours left in the day.

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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:** [20 December 2023 00:37 UTC](https://discourse.nodered.org/t/node-red-contrib-modbus-problem-with-modbus-serie/83038/25 "2023-12-20T00:37:14Z")

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Closed on 20 December 2023 00:37 UTC

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