# MQTT Subscription
**URL:** https://discourse.nodered.org/t/mqtt-subscription/25931
**Category:** Dashboard
**Created:** [2 May 2020 15:23 UTC](https://discourse.nodered.org/t/mqtt-subscription/25931 "2020-05-02T15:23:22Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@ritwikris26](https://discourse.nodered.org/u/ritwikris26)
#### Post date: [2 May 2020 15:23 UTC](https://discourse.nodered.org/t/mqtt-subscription/25931/1 "2020-05-02T15:23:22Z")
Hello
My device takes the value in the JSON format like {Flow:65} where Flow is the Tag name and 65 is the set value when i use inject to MQTT out its working fine but i want to send this by using slider and MQTT out .
Please guide how to use it i tried to insert function in between to add value from slider like
D={Flow:{value}}
return D;
but its not working as output is coming value is not defined
---
### Author:  [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)
#### Post date: [2 May 2020 20:57 UTC](https://discourse.nodered.org/t/mqtt-subscription/25931/2 "2020-05-02T20:57:36Z")
Welcome to the forum.
> [@ritwikris26](#):
>
> Please guide how to use it i tried to insert function in between to add value from slider like
> D={Flow:{value}}
> return D;
It isn't at all clear where you are putting that code. Is that in a function node? If so, you need to go back and look again how data is passed into a function node and how it is passed out again.
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### Author:  [@ritwikris26](https://discourse.nodered.org/u/ritwikris26)
#### Post date: [2 May 2020 23:27 UTC](https://discourse.nodered.org/t/mqtt-subscription/25931/3 "2020-05-02T23:27:45Z")
I am using a slider to pass data to function node. And i want the output of function node to be in this format {"Flow":value} where value should come from slider.
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### Author:  [@dceejay](https://discourse.nodered.org/u/dceejay)
#### Post date: [3 May 2020 09:27 UTC](https://discourse.nodered.org/t/mqtt-subscription/25931/4 "2020-05-03T09:27:15Z")
maybe try
```auto
msg.payload = { Flow : msg.payload };
return msg
```
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### Author:  [@ritwikris26](https://discourse.nodered.org/u/ritwikris26)
#### Post date: [3 May 2020 15:41 UTC](https://discourse.nodered.org/t/mqtt-subscription/25931/5 "2020-05-03T15:41:42Z")
Thanks for your support , its working now.
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### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [17 May 2020 15:41 UTC](https://discourse.nodered.org/t/mqtt-subscription/25931/6 "2020-05-17T15:41:44Z")
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