# SOLVED: ELRO AB400 power switch 433 MHz // RFXtrx
**URL:** https://discourse.nodered.org/t/solved-elro-ab400-power-switch-433-mhz-rfxtrx/25821
**Category:** Hardware
**Created:** [30 April 2020 15:08 UTC](https://discourse.nodered.org/t/solved-elro-ab400-power-switch-433-mhz-rfxtrx/25821 "2020-04-30T15:08:04Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@duaw](https://discourse.nodered.org/u/duaw)
#### Post date: [30 April 2020 15:08 UTC](https://discourse.nodered.org/t/solved-elro-ab400-power-switch-433-mhz-rfxtrx/25821/1 "2020-04-30T15:08:04Z")
Hi guys,
I have an ELRO AB440S switch, 433 MHz, not exactly new anymore, but similar types seem still to be very common. They are cheap.
On the device you set a "System Code" and a "Unit-Code" via 10 DIP switches. Mine is set to "30" (5 possible switches 0..31) and "B" (one out of 5 possible switches)
I managed to switch the device via "[Tinkerforge](https://www.tinkerforge.com/en/)" hardware (nice stuff, check it out!) as a "Type A Switch" with given "House Code" (30) and "Receiver Code" (B). I also have an RFXtrx USB RF transceiver.
Then I found **node-red-contrib-rfxcom**.
**rfx-lights** come to the rescue! This is the node I need!
The topic is in my case **ELRO/H/11** with payload On/Off.
H and 11??? Why that? Well, ... my setting of DIP-Switches on the device
```auto
Syst.|Unit -
12345|ABCDE
01111|01000
30| B
```
is translated (according to the table in the RFXtrx documentation) to
```auto
1234|5ABCD
0111|10100
H|11
```
The **4** DIP switches 1...4 define (0000) A ... (1111) P, the **5** DIP switches 5, A ... D define (00000) 1 ... (11111) 32
Took me a while to figure this out. Thanks to maxwellhadley!
Uwe
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### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [29 June 2020 15:08 UTC](https://discourse.nodered.org/t/solved-elro-ab400-power-switch-433-mhz-rfxtrx/25821/2 "2020-06-29T15:08:05Z")
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