Wegener Communications 4422 - Manual (Page 17)

Page 17
Page 17 of 72 UTY4422-002
The main host processor runs the control system on the main board. This processor interfaces
with the
COMPEL ™ network as well as local users and then controls and monitors the unit’s
operations. To do its job, this processor accesses the control data streams recovered from the
main transport demultiplexer. One of these may be a Conditional Access data stream (if used).
The main processor sends this data to a separate secure microprocessor, which looks to see if its
unit serial number is authorized to receive the broadcast signal and, if so, recovers the secret
keys for decrypting the incoming encrypted transport stream. Meanwhile, the main host
processor also communicates with several peripheral devices. It manages the data passed
to/from the front-panel keypad controller (which lights status LED's, manages an LCD display,
and reads back keypresses). It manages two serial ports that allow for use of a terminal, modem,
printer, or auxiliary data device as well as the display and printing of local e-mail. Additionally,
it controls the L-band receiver daughtercard and any installed Options Modules.
For maximum flexibility, and to make value-added upgrades easily possible, the operating unit
software is stored in flash memory and may be dynamically replaced via the local serial port or
from the satellite network control channel.
2.3 SPECIFICATIONS
The UNITY4422 can be factory-configured for a tuner- QPSK Demodulator input, or for a DVB-
ASI Input. The difference is whether the tuner card or DVB card is installed. The unit can auto-
detect whether a tuner or DVB input card is installed in order to do field troubleshooting, but if a
field modification is being done the boot code will need to be changed. Also, when the boot
code is changed the app and dsp codes will need to be loaded into the unit. This allows one
software package to be installed in a number of different unit configurations, and simplifies
updating that software.
2.3.1 Transport DEMUX
The transport demux is used to extract the desired video and audio streams from the multiplexed
data stream.
2.3.2 System Processor
The main system processor is an extended architecture processor, and uses flash memory for
microcode storage with download capability via either terminal or satellite channel.
The unit also has an
MPEG 2 video processor ASIC , and an audio processor ASIC .
2.3.3 Auxiliary Data Processing
An asynchronous user-data stream embedded in the transport stream may be routed to SERIAL 1
or SERIAL 2 ports under user or network control.
2.3.4 Composite Video Encoder
The unit supports the following video resolutions: