TIMTER™ Multi-mode Digital Telemetry Transmitter
63
Quasonix, Inc.
Actual Output Freq set to 2200.200000 MHz
PCMFM>FR 1812.56789
Freq set to 1812.5 MHz
Freq offset currently 0.067890 MHz
Actual Output Freq currently 1812.567890 MHz
4.2.1.1.8 Frequency
– FR
When programming a transmitter using a digital switch box, the switch box displays an error light if the user tries to
program a frequency outside the range. Note that the transmitter allows up to 10 MHz outside of the standard
defined frequency range, however this is not recommended, and behavior outside the range is not guaranteed. The
switch box will send the appropriate value to the transmitter, but will still flash an error to indicate the value is
outside the frequency range. If the frequency value passes 10 MHz, the transmitter displays a frequency not set
message.
The example below shows a display from a Terminal session. The first line shows a message sent from the switch
box (indicated by SWBX) with a frequency of 2200.5 MHz. The second line shows a frequency of 2190.5. The third
line shows an attempt to change the frequency to 2190.0, which is 10.5 MHz outside the standard frequency range.
In this case, the desired frequency was not set.
1_SOQPSK>SWBX Chan 1, Freq set to 2200.5 MHz
1_SOQPSK>SWBX Chan 1, Freq set to 2190.5 MHz
1_SOQPSK>SWBX Chan 1, Freq Invalid (2190.0 MHz). Freq NOT set
4.2.1.1.9 Internal Clock Rate
– IC
This rate is used if the clock source is set to internal (CS 1). It should not be confused with “BR”, which sets the rate
of the internal bit sync, which phase locks to the externally applied data, if Clock-free is enabled.
If no argument is passed, the unit reports the clock frequency. If a valid frequency is given, the internal clock
frequency is set. The frequency is in MHz.
The units used to describe the internal bit rate are sometimes used interchangeably, and may cause confusion.
Megahertz (MHz) and Hertz (Hz) are cycles per second units, while Mbps (megabits per second) and bps (bits per
second) are data rate units.
The internal clock is referred to as “clock,” so Hz or MHz is often used as the unit, since “clock” is a frequency.
If the clock is used to “clock” the bits at X MHz, then the throughput in bits is X Mbps. In other words, the internal
clock also sets the baseband bitrate. That is why, in this case, units of Hz are equated with units of bps.
For example, 5,000,000 Hz or bps may be rewritten as 5.000 MHz or 5.000 Mbps.
4.2.1.1.10 Input Source Selection Command
– IS
The IS command is used to select the clock and data source (and the user pattern and clock rate where applicable)
for the transmitter with one command. This command can conceivably replace CS, DS, ID, IC, BR, BT, AIR, CF,
and EN.
This command is standard on all units version 2.409 or greater.
Syntax: IS [ds/?/pnxx/XXXX [cs/AUTO/rate]]
where
ds
is data source which can be:
ET – external TTL data
(if QSX-VxT or -VR enabled)
Содержание TIMTER QSX-V Series
Страница 39: ...TIMTER Multi mode Digital Telemetry Transmitter 31 Quasonix Inc Figure 22 Baseband Signal Timing ...
Страница 101: ...TIMTER Multi mode Digital Telemetry Transmitter 93 Quasonix Inc Figure 41 Shock Pulse X axis Negative ...
Страница 109: ...TIMTER Multi mode Digital Telemetry Transmitter 101 Quasonix Inc Figure 42 Transmitter Clock and Data Logic ...
