Copyright 2011-2020, RFXCOM
RFXtrx Version 5.68
page 61 / 70
21. FAQ
21.1. Receive has stopped suddenly but transmit works.
Most probably a sensor is transmitting constantly. This could be for example an X10 MS13 motion
sensor or weather sensor with almost empty battery. Or an outside weather sensor filled with
water. Or a remote with a button pressed.
Test the RFXtrx with a remote or sensor on another location (> 1km away) using RFXmngr on a
Windows system or laptop.
21.2. Can I increase the receive/transmit range of the RFXtrx?
First check chapter 2.5 for the best place for the RFXtrx antenna.
The switch board is not the best place for the RFXtrx because of all metal objects that will absorb
or reflect the RF signals.
It is also advised to place the RFXtrx far away from PC’s, routers, Raspberry PI … because of the
RF noise those products produce, and this will reduce the receive range very much.
You can connect another 50ohm 70cm/433MHz antenna with more gain.
For example,
http://www.ebay.com/itm/290979680030
Install this antenna on a metal plate of at least 30 cm for optimum result.
21.3. The RFXtrx USB connection disconnects sometimes.
This happens mostly on Raspberry PI with a low-quality power supply. Solution is to use a
powered USB hub with a good quality power supply.
It can also happen if the USB cable is running along a power cable or a power device is switched
on that produces a high-power spike like a fluorescent tube. Solution is to separate the USB cable
from all other cables and/or use a powered USB hub with a good quality power supply.
21.4. I have a 433.92MHz sensor/remote but this device is not received.
Besides the frequency the used protocol and modulation type is also important.
See chapter 2 for the list of supported devices.
21.5. The wall plug is switched by the remote, the remote is received
but the RFXtrx does not switch the module.
The remote transmits several protocols. The protocol used by the wall plug is not received by the
RFXtrx but some other protocols are received.
Solution:
For the HomeEasy EU- HE8xx series: reset the module to remove all paired remotes and pair the
module with the RFXtrx433E and one of remote codes that is received.
For IT modules FA500/PROmax: Pair the RFXtrx433E with the module using an IT device and
select a random ID. The received remote code can be used to know if the module is switched by
the remote.