# Limit a signal or payload?
**URL:** https://discourse.nodered.org/t/limit-a-signal-or-payload/37911
**Category:** General
**Created:** [23 December 2020 10:32 UTC](https://discourse.nodered.org/t/limit-a-signal-or-payload/37911 "2020-12-23T10:32:33Z")
**Posts on this page:** 10
**Page:** 1
### Author:  [@Steinspiel](https://discourse.nodered.org/u/Steinspiel)
#### Post date: [23 December 2020 10:32 UTC](https://discourse.nodered.org/t/limit-a-signal-or-payload/37911/1 "2020-12-23T10:32:34Z")
Hello,
Does anyone know a solution for my problem:
An "mqtt-in" sends a String: "ON" every 8 seconds. This activates an "openHAB\_Switch\_Item". If the transmission is interrupted by "mqtt-in" for more than 20 seconds, a "trigger node" sends a String: "OFF" and the "openHAB\_Switch\_Item" is switched off.
That works and it's all OK!
Which node do I have to put between "mqtt-in" and "openHAB\_Switch\_Item" so that an "ON" is only sent **once** and not every 8 seconds? And how do I have to configure this node?
So sends "mqtt-in", then once "ON" until the "trigger node" "OFF" switch. Sends "mqtt-in" again, then again "ON" etc.
Do you understand what I mean?
```auto
[{"id":"66b37773.104628","type":"tab","label":"Flow 3","disabled":false,"info":""},{"id":"6d48a4d2.67b09c","type":"inject","z":"66b37773.104628","name":"MQTT Broker","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"ON","payloadType":"str","x":570,"y":420,"wires":[["8afbb924.857ce8","d1901a6c.7558a8"]]},{"id":"8afbb924.857ce8","type":"openhab2-out","z":"66b37773.104628","name":"openHAB Switch Item","controller":"","itemname":"GTag_NR_gruen","topic":"ItemCommand","payload":"","x":1110,"y":420,"wires":[[]]},{"id":"d1901a6c.7558a8","type":"trigger","z":"66b37773.104628","name":"","op1":"","op2":"OFF","op1type":"nul","op2type":"str","duration":"20","extend":true,"overrideDelay":false,"units":"s","reset":"","bytopic":"all","topic":"topic","outputs":1,"x":840,"y":360,"wires":[["8afbb924.857ce8"]]}]
```
Thank you and have a healthy Christmas
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [23 December 2020 10:49 UTC](https://discourse.nodered.org/t/limit-a-signal-or-payload/37911/2 "2020-12-23T10:49:16Z")
> [@Steinspiel](#):
>
> Which node do I have to put between "mqtt-in" and "openHAB\_Switch\_Item" so that an "ON" is only sent **once** and not every 8 seconds
An RBE node should do the job.
PS, did you make that graphic (or find it)?
---
### Author:  [@Steinspiel](https://discourse.nodered.org/u/Steinspiel)
#### Post date: [23 December 2020 12:54 UTC](https://discourse.nodered.org/t/limit-a-signal-or-payload/37911/3 "2020-12-23T12:54:57Z")
> [@Steve-Mcl](#):
>
> An RBE node should do the job.
The "rbe-node" is great! 🙂
Thanks, it works great. That's exactly what I wanted.
> [@](#):
>
> PS, did you make that graphic (or find it)?
I made the graphics myself, I think a picture explains it better.
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [23 December 2020 14:01 UTC](https://discourse.nodered.org/t/limit-a-signal-or-payload/37911/4 "2020-12-23T14:01:01Z")
> [@Steinspiel](#):
>
> I think a picture explains it better.
It does. How did you make it (if you dont mind)?
---
### Author:  [@Steinspiel](https://discourse.nodered.org/u/Steinspiel)
#### Post date: [23 December 2020 17:22 UTC](https://discourse.nodered.org/t/limit-a-signal-or-payload/37911/5 "2020-12-23T17:22:33Z")
> [@Steve-Mcl](#):
>
> It does. How did you make it (if you dont mind)?
That with the picture is quickly explained:
- a screenshot of the Node-Red Flow -\>
- in GIMP a "\*.png" with transparent background was created from it -\>
- rendered an "arrow sign animation" with BLENDER [https://www.youtube.com/watch?v=C9ZVSxzh6JA](https://www.youtube.com/watch?v=C9ZVSxzh6JA) -\>
- "_.png" and animation with text added in a video editor and a "_.mp4" video created -\>
- the video converted into an animated GIF with Instagiffer [https://instagiffer.com/](https://instagiffer.com/) -\>
- uploaded the "\*.gif" to Imgur [https://imgur.com/](https://imgur.com/) -\>
- added the Imgur "BBCode" to the forum post
If you have any further questions, feel free to ask ...
a good evening
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [23 December 2020 17:25 UTC](https://discourse.nodered.org/t/limit-a-signal-or-payload/37911/6 "2020-12-23T17:25:29Z")
Thats quite some task - i thought there was some nice and easy web site or application 😉
PS, there is no need for last 2 steps (you can drag and drop the gif straight into the reply)
* * *
Thanks for the reply.
---
### Author:  [@Steinspiel](https://discourse.nodered.org/u/Steinspiel)
#### Post date: [23 December 2020 23:17 UTC](https://discourse.nodered.org/t/limit-a-signal-or-payload/37911/7 "2020-12-23T23:17:27Z")
> [@Steve-Mcl](#):
>
> PS, there is no need for last 2 steps (you can drag and drop the gif straight into the reply)
Oh I did not know that!
I will try it...
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [23 December 2020 23:20 UTC](https://discourse.nodered.org/t/limit-a-signal-or-payload/37911/8 "2020-12-23T23:20:54Z")
In fact if the image data is in your clipboard, you can paste that straight into a reply too. (i.e. i often use greenshot or ImageX to do an screenshot image snippet, annotate it, then copy+paste it straight into a reply
e.g.. no files were hurt in the making of this clipboard screenshot ...
---
### Author:  [@Steinspiel](https://discourse.nodered.org/u/Steinspiel)
#### Post date: [24 December 2020 10:23 UTC](https://discourse.nodered.org/t/limit-a-signal-or-payload/37911/9 "2020-12-24T10:23:37Z")
Moin,
> [@Steve-Mcl](#):
>
> you can paste that straight into a reply too.
It's a very cool method!
I will use them in the future ...
Thank you and I wish you a happy and healthy Christmas...
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [22 February 2021 10:23 UTC](https://discourse.nodered.org/t/limit-a-signal-or-payload/37911/10 "2021-02-22T10:23:41Z")
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