# Send json tcp request

**URL:** <https://discourse.nodered.org/t/send-json-tcp-request/12653>\
**Category:** General\
**Created:** [27 June 2019 11:11 UTC](https://discourse.nodered.org/t/send-json-tcp-request/12653 "2019-06-27T11:11:08Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Kayle](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/kayle/32/9686_2.png) [@Kayle](https://discourse.nodered.org/u/Kayle)\
**Post date:** [27 June 2019 11:11 UTC](https://discourse.nodered.org/t/send-json-tcp-request/12653/1 "2019-06-27T11:11:08Z")

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Hello all,

I'm trying to get data from my 3d printer through tcp port 35. I was able to sniff the packages between my computer and the printer with wireshark, but I was not able to get data with node red. It seems that there is a communication with custom json. I've tried to inject the json data directly through the tcp request node but I got a connection error.

I've attached some pictures of the wireshark dump because I am not able to upload the dump as zip file.

 ![host-printer_1](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/f/f2c234840017d03df91f93786826d52c1396921a.jpeg) ![host-printer_2](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/5/5df7ed5110630e76c588118be8642e91b2c273cb.jpeg)

There are 3 packages sent repeatedly:

1. from the host to the printer with a length of 54 bytes
2. from the host to the printer with a length of 183 bytes including the json data
3. from the printer to the host with a length of 775 bytes with the result

Is there anyone who is familiar with wireshark who can help me here?

Thanks in advance  
Kay

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<div class="post-metadata">

**Author:** ![Kayle](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/kayle/32/9686_2.png) [@Kayle](https://discourse.nodered.org/u/Kayle)\
**Post date:** [27 June 2019 11:31 UTC](https://discourse.nodered.org/t/send-json-tcp-request/12653/2 "2019-06-27T11:31:44Z")

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![printer_host_result](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/9/9b7210e93e05ba392b2e824319a49d56a55a093b.jpeg)

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**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [27 June 2019 15:15 UTC](https://discourse.nodered.org/t/send-json-tcp-request/12653/3 "2019-06-27T15:15:36Z")

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you need to check that you can connect to port 35 - quite often ports below 1024 are only available to root by default.

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**Author:** ![Kayle](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/kayle/32/9686_2.png) [@Kayle](https://discourse.nodered.org/u/Kayle)\
**Post date:** [28 June 2019 05:49 UTC](https://discourse.nodered.org/t/send-json-tcp-request/12653/4 "2019-06-28T05:49:08Z")

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Yes, you are right. Thanks for pointing. I will check that.

Kay