Measuring RSSI Voltage
To measure the receiver module RSSI voltage:
1.
Set a voltmeter to DC volts and 5 volt range
2.
Connect the voltmeter between VOLT (+) lead and GND ( - ) lead.
This voltage measurement indicates direct ambient RF noise; it is not
affected by the VR1 RSSI control circuitry. A lower voltage means less
ambient RF noise. A higher voltage means more ambient RF noise. This
directly affects reception distance and quality.
RF NOISE
RF noise reception affects range and signal readability, the lower the RSSI
voltage the better quality of signal is being received. The SFR-200 receiver
module has more filtering and better range, but it has its limitations in
certain environments.
Typical Office Area
Average RSSI Voltage
no antenna
0.4V
with antenna
0.55V to 0.6V
A reading in the 1V range means that there is a high level of ambient RF
noise at the receiver. You may have to move the receiver away from the
source of the noise.
When measuring the RSSI voltage, if you activate a SmartFob transmitter by
pressing one of the buttons, the voltage will jump to the 1V range. This is an
indicator of the strength of the RF transmission signal relative to the
ambient RF noise.
Smartfob Receiver MN: SFR2RXB
Page 13 of 17
Installation Manual
July 2008 • Rev. 1.0
