FreeWave Technologies Inc. 1293514195135 Manual De Usuario

LRS400S Data Transceiver Users Manual 

LUM0025AA Rev A 

Version 1.0 

18 

FreeWave transceivers utilize a Master Transmit Beacon to provide low current consumption in the slave 
radios. The slave radios will turn their receiver off when no data is being passed. 

The Xmit Rate setting allows the duty cycle of the Master Transmit Beacon to be changed. A setting of 0 
is the highest duty cycle and a setting of 9 is the lowest duty cycle. 

FreeWave transceivers have five settings for the RF Data Rate (1, 2, 3, 4, 5 ). RF Data Rate should not 
be confused with the serial port Baud Rate.  

Setting 2 should be used when the transceivers are close together and data throughput needs to be 
optimized. Setting 3 should be used when the transceivers are farther away and a solid data link is 
preferred over data throughput. 

Note:   In MultiPoint networks, the RF Data Rate must be set identically in all transceivers. Any 

transceiver with an RF Data Rate different from the Master will not establish a link.   

In Point to Point networks the Master’s settings take precedence over the Slave. 

RF Data Rate Setting 

Occupied Bandwidth 

Modulation Level 

1 50kHz 

2-level 

GFSK 

2 25kHz 

4-level 

GFSK 

3 25kHz 

2-level 

GFSK 

4 12.5kHz 

4-level 

GFSK 

5 12.5kHz 

2-level 

GFSK 

 

 

The RF Xmit Power parameter allows the user to control the output transmit power up to two watts 
(+33dBm). 

Note:  For use in applications requiring greater than 70% transmit duty cycle, the LRS400S series of 

radios must be attached to an appropriate heat sync. 

The following table shows RF TX output versus the RF Xmit Power setting. 

RF Xmit 

Power 

RF TX 
Power 

(dBm) 

RF Xmit 

Power 

RF TX 
Power 

(dBm) 

RF Xmit 

Power 

RF TX 
Power 

(dBm) 

RF Xmit 

Power 

RF TX 
Power 

(dBm) 

10 +33 7 +30 4 +27 1 +24 

9 +32 6 +29 3 +26 0 +23 

8 +31 5 +28 2 +25