Company Confidential
8
Raveon Technologies Corp.
6.
Tune-up and Alignment
The
RV-PMTII
modem has been factory calibrated, in should not require any re-
calibration when installed. The unit cannot be tuned or adjusted without the
proper test board. The following section assumes access to the required test
board.
This unit is sensitive to input voltage. Improperly attempting to connect to
the unit could result in permanent damage.
6.1. Periodic Calibration
The only setting that may require adjustment is the center frequency. After years
of operation, all crystals will age and change frequency slightly. Like all narrow-
band radios, semi-annual checks and adjustment of frequency is recommended.
6.2. Calibration Commands
The following AT commands are used to calibrate the PMTII when connected to
a test board. 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
**
