Specifications

RV-M7 Technical Manual
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ATMY The ID of this unit. Default is 1234.
ATMK The network address mask. Default is FFFF.
ATDT The address of the unit this modem will talk to. Default is 1234.
6. Connect your serial data device to the 9-pin connector on the front of the modem.
The radio is now ready to use. Any serial data going into the modem will be transmitted over the
air, and any data received over the air will be sent out the serial port.
Remember, that from the factory, all M7 modems are configured to simply work. Plug in power and
connect to the serial port at 9600 baud, and the modems will communicate on the default channel.
Change the channel frequency to your specific frequency, and they will be ready to work on your
channel.
6.2 Programming Channels and Frequencies
The M7 modem has memory for up to 6 channels. A channel is a pair of frequencies, one for
transmit and one for receive. They may be different or they may be the same. You may program
any valid frequency into any channel number. To program a channel, perform the following steps.
1. Change to the channel you wish to program, using the ATHP x command, where x is the
channel number.
2. Program the frequency for this channel x, using the ATFT, ATFR, or ATFX command. Note
that the frequency my be entered in MHz as long as you use a decimal point. For Example,
enter ATFX 450.1 to set the channel frequency to 450.100MHz. Alternately, you may enter
the frequency in hertz by entering ATFX 450100000. You must enter all of the zeros if you
enter the frequency in hertz.
3. Review the frequency setting with the ATFT, ATFR, or ATFX command. To see a list of all of
the channels , enter ATF.
4. To change the radio channel, use the ATHP x command while the modem is in the command
mode.
6.3 Data Transmission
To transmit data, send one or more bytes of data into the serial port of the modem. When a full
packet of data has been collected into the internal buffer of the modem, or when there is a pause in
the data, the modem will automatically key its transmitter, and send the data over the air.
Serial Port Baud Rate
While the modem is transmitting, the user may continue to send more data into the M7. Because
the buffers in the M7 are full-duplex, the serial port data rate and the over-the-air data rates are
independent. The serial port baud-rates may be set slow to accommodate legacy equipment, or set
at high-speed to minimize latency. The over-the-air data rate us usually 4800 baud for narrow-band
channels, and 9600 baud for wide-band, although faster or slower rates may be used.
In Packet Mode, selection of the serial port baud-rate is important. As shown above, if the serial
port baud-rate is the same as the over-the-air baud rate and the packets are short, the channel