Specifications

RV-M7 Technical Manual
45
7.6 Setting the Over-The-Air Data Rate
The M7 has programmable over-the-air baud rates. The over-the-air rate is stored in register R2,
and is programmed with the ATR2 x command, where x is a number corresponding to the rate. The
are many possible baud rates, but not all rates may be used with all radio modem models. Consult
the following table.
Over-the-air rate
Radio Bandwidth
Number of
Modulation
Levels
M7 Modem Models that support
the rates
800bps (R2=0)
12.5kHz or 25kHz
2
RV-M7-UC-N, RV-M7-UC-W
1200bps (R2=1)
12.5kHz or 25kHz
2
RV-M7-UC-N, RV-M7-UC-W
2400bps (R2=2)
12.5kHz or 25kHz
2
RV-M7-UC-N, RV-M7-UC-W
4800bps (R2=3)
Default setting
12.5kHz or 25kHz
2
RV-M7-UC-N, RV-M7-UC-W
8000bps (R2=4)
12.5kHz or 25kHz
4
RV-M7-UC-N, RV-M7-UC-W
9600bps (R2=5)
25kHz
2
RV-M7-UC-W only
19200bps (R2=6)
25kHz
4
RV-M7-UC-W
(will not work with Radio Type 5)
5142bps (R2=7)
12.5kHz or 25kHz
2
RV-M7-UC-N, RV-M7-UC-W, RV-M7-UC-S
9600bps (R2=8)
12.5kHz or 25kHz
4
RV-M7-UC-N, RV-M7-UC-W
Changing the over-the-air data rate will change the sensitivity of the receiver. Higher-data rates
require a stronger signal at the receiver to be properly received. The default over-the-air data rate
for M7 radio modems is 4800 baud for narrow-band versions, and 9600 baud for wide-band
versions.
The maximum over-the-air baud-rate for a narrow-band radio (12.5kHz channel-spacing) is 9600bps.
Due to IF filter limitations, the M7 does not work as well at 9600 baud as some other rates. Its
performance is optimized for 4800 baud 2-level modulation and 8000 baud 4-level modulation.
The maximum over-the-air baud-rate for a wide-band model (25kHz channel spacing) is 19200bps.
Due to IF filter limitations, it does not work as well at 19200 baud as lower data rates. Its
performance is optimized for 9600 baud 2-level modulation.
RV-M7-UC (narrow-band version)
Factory default, set R2 to 3 (4800 baud).
For high-speed operation, set R2 to 4 (8000 baud).
For best range (longest distance), set R2 to 1 (1200 baud)