User Manual
23 Raveon Technologies Corp.
10.2. Calibration Commands
The following AT commands are used to calibrate the M8. Do not ever change
these unless you have been factory trained to do so.
AT
Command
Command Description
Parameters
Factory
Default
R0
Symbol Peak Deviation – Set the peak FM deviation of
the transmit symbols. Note: This can be a negative
number to invert the modulation.
Range: -1000 – 1000
120**
R1
Select CD pin output signal – CD pin may be RF
carrier detect, or modem data detect, off, on, or RX data
framing, or on-line status. Line status mode asserts CD
when on-line in normal modem operation and it negates
CD when in the command mode.
Range : 0 - 5
5 = RX data framing. Assert
when outputting data
4 = Line stat.
3 = Always negate CD
2 = Always assert CD
1 = Data CD
0 = RF CD
0
(RF Carrier)
R2
Over-The-Air bit rate - This is the data rate the radio
uses to send data over the air. All RF modems in the
network must use the same over-the-air baud rate.
Range:
0 = 800 5 = 9600 2L
1 = 1200 6 = 19200 4L
2 = 2400 7 = 5142 2L
3 = 4800 8 = 9600 4L
4 = 8000 4L 9 = 2000 2L
3
R3
Serial Port time out – Number of mS of no activity on
the serial port before transmitting the data in its buffer.
Range: 1 - 5000
20 (mS)
R5
Preamble length – The number of bytes to send over-
the-air in the pre-amble.
Range: 3 - 255
4**
(Varies based
on data rate
and radio
type. 7 typical)
R8
Frequency Offset. Used to set the radio on the center of
the radio channel.
Range: -500 to +500
0**
R9
Modulation Balance.
Range: 0-100
20**
RA
Select RF CD output threshold – This value is the
RSSI threshold where the carrier detect is asserted.
Note: To force CD always on, set this to 0, and R1 to RF
Carrier Detect.
Range : 0 thru -127
-110
10.3. Center Frequency
1. Key the transmitter with CW output using this command:
ATTD 7
2. The modem will now put out CW on the center of the channel.
3. Read the frequency offset with the ATR8 command.
4. Adjust the frequency to the center of the channel with the ATR8
command. You can use the “U” key and the “D” key to change the
settings up and down one value in real time.