tr2m-458-5 Radiometrix Ltd, tr2m-458-5 Datasheet - Page 5

• Manufacturer Part Number: tr2m-458-5
• Description: Multinarrow Band Fm Multi-channel Uhf Transceiver
• Manufacturer: Radiometrix Ltd

If the microcontroller has a built-in Analogue to Digital Converter (ADC), the Received Signal Strength
Indicator (RSSI) output voltage level can be read by the microcontroller to estimate its distance from
transmitting TR2M unit or identify areas of weak signal reception.
RSSI can also be used to make a decision to switch to the second antenna in fixed installations within
building where the probability of null-spots are higher.
There is a generic 10% duty cycle restriction on the 433MHz ISM band through out European countries
with few exceptions. Annex 1 Band E, Band E2 of European Radio Communications Committee (ERC)
Recommendation 70-03 dated February 2004 specifies the following:
433.050MHz (Ch0)
433.05MHz
433.050-434.790 MHz, Non Specific Short Range Device, band is primarily intended for Telemetry,
Telecommand, Alarms, Data in general and other similar applications. Audio and Voice signals should
be avoided in the band.
Radiometrix Ltd
2.5
2.3
2.1
1.9
1.7
1.5
1.3
1.1
0.9
0.7
0.5
-130
Figure 5: RSSI voltage variation with respect to RF level at TR2M
-120
for Channelised Narrow Band and Wide Band usage
-110
10mW ERP, 10% duty cycle
Regulatory Restrictions
-100
434.040MHz
TR2M Data Sheet
RF Level (dBm)
434.050MHz (Ch40)
-90
for <25kHz Channelised Narrow Band usage
-80
10mW ERP, 100% duty cycle
-70
-60
-50
433.775MHz (Ch69)
-40
434.79MHz
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