# Field in TTN Uplink node

**URL:** https://discourse.nodered.org/t/field-in-ttn-uplink-node/18641
**Category:** General
**Created:** [30 November 2019 21:16 UTC](https://discourse.nodered.org/t/field-in-ttn-uplink-node/18641 "2019-11-30T21:16:41Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![molly](https://avatars.discourse-cdn.com/v4/letter/m/df788c/32.png) [@molly](https://discourse.nodered.org/u/molly)
#### Post date: [30 November 2019 21:16 UTC](https://discourse.nodered.org/t/field-in-ttn-uplink-node/18641/1 "2019-11-30T21:16:41Z")

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Hi,  
I wanna to define the Field in TTN Uplink, so only one payload can be the output. But in fact, after I defined this to 'humidity' or 'payload.humidity' or 'payload\_fields.humidity', there has no change. I am so condused how can I define this in the correct way？  
Thanks very much!!!

 ![1](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/8/80efa5c17ba0c7000fc9a41fbd6fb8ac0fe6013b.jpeg)