Internal Clock Rate – Ic - Quasonix TIMTER Installation And Operation Manual

9 Manual control with NIOS TX DI pin in CMNIO
'?' displays a syntax listing
Examples:
CG 5 // Set CG output to external clock always
CG ? // Display the choices
Internal Clock Rate – IC
4.2.3.1.3
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.
Low Density Parity Check Command – LD
4.2.3.1.4
The LD command enables or disables the Low Density Parity Check coding on a dual transmitter. This is only valid
in *PSK modes, and it automatically turns OFF differential encoding. When LDPC is disabled, the state of DE is
determined by the mode (eg. all *PSK modes default to DE On.)
In the Dual Transmitter, the LD command operates on the currently selected channel(s).
There is an optional selection for the block and rate selection. This requires purchase of the LD6 option which
enables LD and enables user code selection. LD6 also allows the randomizer command (RA or RN) to select
CCSDS if LDPC is enabled.
The default code is 4096 2/3.
If the transmitter includes the LD option (but not LD6), then LD 0 or LD 1 are used to disable or enable LDPC,
as shown in the example immediately following. With the LD option, the block size and code rate are always 4096
2/3.
Examples:
LD Show the current encoder state
LD 1 Enable the LDPC encoder
LD 0 Disable the LDPC encoder
If the transmitter includes the LD6 option, the user may select from the six implemented LDPC codes. This also
allows user selection of the CCSDS randomizer using the RA or RN command. Adding LD6 automatically enables
the existing LD option.
73 Quasonix, Inc.
TIMTER™ Multi-mode Dual
Telemetry Transmitter