TIMTER™ Multi-mode Digital Telemetry Transmitter
66
Quasonix, Inc.
•
XX.xxx for clock free with BR = XX.xxx
Actions
: ds 0, cs 0, ai 1, cf 0 AIR 1 br XX.xxx
(en 0 if needed)
If ds = EN, then cs MAY be:
•
Nothing (defaults to Ethernet clock at current IC rate) (displayed)
Actions
: ds 0, cs 0, en 1 (cf 1 if needed) (ai 0 if needed)
•
EN for Ethernet clock at current IC rate) (displayed)
Actions
:: ds 0, cs 0, en 1 (cf 1 if needed) (ai 0 if needed)
•
XX.xxx for Ethernet clock with ic = XX.xxx
: ds 0, cs 0, en 1 ic XX.xxx (cf 1 if needed) (ai 0 if needed)
Notes:
•
Numbers need only as many significant digits as necessary. For example, to specify 10 Mbps (for either BR
or IC) you can enter 10, 10.0, 10.000, etc.
•
Some command versions require the unit to have specific options and will not work without those options.
For instance, you cannot specify EN for Ethernet unless the unit has the -EN option in the part number.
•
While this command incorporates the functionality of nine (9) or more commands, those commands are
still usable. For example, if the unit has the -VR option then the BT command can still be used by itself to
switch between TTL and RS-422 inputs for clock and data.
Examples:
IS ET
Sets unit to
‘normal’ mode expecting external TTL clock and data to be applied to the unit
inputs
IS PN15 4.5
Sets unit to internal clock/data with a PN15 pattern at 4.5 Mbps
IS AT AUTO
Sets unit to use the auxiliary TTL input in clock free mode with auto bit rate enabled
IS EN 10
Sets unit to use the Ethernet interface for both clock and data and to set the desired bit
rate to 10 Mbps
4.2.1.1.11 Low Density Parity Check (LDPC) Command
– LD
The LD command enables, disables, and shows the current state of the Forward Error Correction (FEC) / Low
Density Parity Check (LDPC) encoder. 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.
This is only valid in *PSK modes (not PCM/FM or MHCPM), and it automatically turns OFF differential encoding.
When LDPC is disabled, the state of DE is determined by the mode (for example, all *PSK modes default to DE
On.)
LDPC cannot be enabled if CC (convolutional encoding) is enabled.
LDPC cannot be set with MC enabled (NRZ-L only).
LDPC is disabled when a mode change occurs. This is true for all mode changes, *PSK or other modes. There are
two exceptions: If preset 0 has LDPC enabled, it stays enabled after a power cycle. Any preset that has LDPC
enabled, stays enabled after the preset is recalled (RC command).
