System description
13
Siemens AB
Security Products
03.2014
3.4.5 Signal strength
Radio waves from any source spread out and thus become weaker with distance
from the source. Each Bewator Entro RF unit displays the strength or weakness of
the received wireless signals.
The RF30-EM shows the signal strength with the help of LEDs. The RF9 shows the
strength of the signal from the controller or intervening router with the help of
LEDs. The SR35i can display the received signal strength. The Entro software can
display the signal strength at SR35i controllers and at RF9 routers.
SR35i and RF30-EM
Below picture shows how mounting of the RF30-EM can be influenced by distance.
Service Mode
Signal strength
Excellent
Sufficient
Marginal
Improvement
recommended
Bad
Improvement
needed
No connection
RF30-EM in
autonomous
mode
25 m (free air)
Fig. 2
Example of how the signal becomes weaker with increasing distance
from SR35i.
SR35i and RF30-EM via a RF9 router
If a RF9 router is added the signal is significantly improved.
Service Mode
Signal strength Excellent
Excellent
Excellent
Excellent
Sufficient
25 m (free air)
Fig. 3
Example of a SR35i with a RF9 router.