Company Confidential
37
Raveon Technologies Corp.
8. Tune-up and Alignment
Do not key the transmitter for more than 30 seconds
out of every 300 seconds. The transmitter is rated at
10% duty cycle maximum.
Radio calibration and alignment is performed using the
ATRx
commands. The
FireLine
modem has been factory calibrated, in should not require any re-
calibration when installed, or when changing frequency or channel. Unless the
user is trained in radio test and calibration, the values stored in the R registers
should not be modified.
Alignment and calibration of the RV-M5-M radio modem must only be performed
by qualified radio service personnel.
Improper adjustment of the radio calibration (R0-R9 and RA registers), can
result in failure of the radio modem.
Calibration and alignment values are stored internal to the modem in the “R”
registers. (R0-R9 and RA). For example, to read R5, issue the
ATR8
command
without any parameter. To change the setting, issue the
ATR8 nn
command,
where nn is the new value you would like to store.
Once you read a register using an ATRx command, you may modify its value by
entering a “U” for up or a “D” for down. U or D will change the value by one. Use
this trick carefully, because it modifies the last R register that was read, and it is
easy to unintentionally modify the wrong register.
8.1.
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. The ATR8
command is used to adjust the center frequency. Like all narrow-band radios,
semi-annual checks and adjustment of frequency is recommended.
8.2.
Radio Module Types
The following table lists the parameters in the modem that are calibrated at the
factory. Calibration values are stored in registers R0 – R9. The
FireLine
radio
modem has the capability of incorporating a variety of different radios modules.
Each different radio model is considered a different “radio type”. The radio type
is read and set with the
ATRT
command.
8.3.
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.
