# Change float value
**URL:** https://discourse.nodered.org/t/change-float-value/68774
**Category:** General
**Created:** [9 October 2022 17:49 UTC](https://discourse.nodered.org/t/change-float-value/68774 "2022-10-09T17:49:35Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@Andre009](https://discourse.nodered.org/u/Andre009)
#### Post date: [9 October 2022 17:49 UTC](https://discourse.nodered.org/t/change-float-value/68774/1 "2022-10-09T17:49:36Z")
Hi,
i want to convert values that I read from my PV system and receive as e.g. fl\_450FF801 so that a correct value is displayed. fl\_450FF801 should become something like 0.34 kW.
How can i change this values and what means fl\_ is it a float value? and to which value must i change it to become the real values behind it? same with value u8, what to do with this value?
i read many topics here but didn't find the right solution, if it's already there please tell me where to find it 😉
Thanks for your help, regards, Andre
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [9 October 2022 17:56 UTC](https://discourse.nodered.org/t/change-float-value/68774/2 "2022-10-09T17:56:46Z")
It would help if you told us the make and model of the device. What does the manual say about values?
---
### Author:  [@Andre009](https://discourse.nodered.org/u/Andre009)
#### Post date: [9 October 2022 18:11 UTC](https://discourse.nodered.org/t/change-float-value/68774/3 "2022-10-09T18:11:08Z")
Hi Steve,
its a SENEC Home v3 and i got these values from an website ([http://ipaddress/lala.cgi](http://ipaddress/lala.cgi)):
i want to work with the values and automat something...
---
### Author:  [@E1cid](https://discourse.nodered.org/u/E1cid)
#### Post date: [9 October 2022 19:46 UTC](https://discourse.nodered.org/t/change-float-value/68774/4 "2022-10-09T19:46:22Z")
This page gives info on types [Query the hidden API of your SENEC photovoltaic appliances](https://blog.odenthal.cc/query-the-hidden-api-of-your-senec-photovoltaik-appliance/)
According to this site this should work] for fl\_ and u8\_
```auto
msg.payload.fl = Buffer.from("fl_42A2E5E4".split("_")[1], 'hex').readFloatBE() // fl_
msg.payload.u8 = Buffer.from("u8_64".split("_")[1], 'hex').readUInt8() //u8_
```
Test flow
```auto
[{"id":"18144789e95d8588","type":"inject","z":"366a43adb328cf95","name":"","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"{\"fl\":\"fl_450FF801\",\"u8\":\"u8_64\"}","payloadType":"json","x":110,"y":460,"wires":[["8a5128bec0bd3db6"]]},{"id":"aefc713a35661715","type":"debug","z":"366a43adb328cf95","name":"debug 11","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":920,"y":380,"wires":[]},{"id":"8a5128bec0bd3db6","type":"function","z":"366a43adb328cf95","name":"function 11","func":"msg.payload.float = Buffer.from(msg.payload.fl.split(\"_\")[1], 'hex').readFloatBE() // fl_\nmsg.payload.uint = Buffer.from(msg.payload.u8.split(\"_\")[1], 'hex').readUInt8() //u8_\n\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":310,"y":500,"wires":[["aefc713a35661715"]]}]
```
---
### Author:  [@Andre009](https://discourse.nodered.org/u/Andre009)
#### Post date: [10 October 2022 06:30 UTC](https://discourse.nodered.org/t/change-float-value/68774/5 "2022-10-10T06:30:00Z")
Hi E1cid, thanks for your help, ok that worked for me.. but only if i have a fixed value in this function node, how can i change this to a variable..
i tried:
msg.payload.fl = Buffer.from("msg.payload.ENERGY.GUI\_HOUSE\_POW".split("_")[1], 'hex').readFloatBE() // fl_
but this didn't work?
---
### Author:  [@E1cid](https://discourse.nodered.org/u/E1cid)
#### Post date: [10 October 2022 06:35 UTC](https://discourse.nodered.org/t/change-float-value/68774/6 "2022-10-10T06:35:14Z")
Try without quotes
```auto
msg.payload.fl = Buffer.from(msg.payload.ENERGY.GUI_HOUSE_POW.split("_")[1], 'hex').readFloatBE()
```
---
### Author:  [@Andre009](https://discourse.nodered.org/u/Andre009)
#### Post date: [10 October 2022 07:08 UTC](https://discourse.nodered.org/t/change-float-value/68774/7 "2022-10-10T07:08:10Z")
small mistake big effect 😉
Now it's working, thanks so much.
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [9 December 2022 07:08 UTC](https://discourse.nodered.org/t/change-float-value/68774/8 "2022-12-09T07:08:44Z")
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