Wegener DVT2000 User manual

PRELIMINARY June 2000
Instruction Manual
MODEL DVT2000™
DIGITAL VIDEO INTEGRATED
TRANSMITTER
Data, drawings, and other material
contained herein are proprietary to
Wegener Communications, Inc., and
may not be reproduced or duplicated in
any form without the prior permission
of Wegener Communications, Inc.
When ordering parts from Wegener
Communications, Inc., be sure to include
the equipment model number, equipment
serial number, and a description of the
part.
In all correspondence with Wegener
Communications, Inc., regarding this
publication, please refer to DVT2000-001C.
First Edition: August 1996
Revised Preliminary: June 2000
WEGENER
COMMUNICATIONSR
TECHNOLOGY PARK / JOHNS CREEK
11350 TECHNOLOGY CIRCLE
DULUTH, GEORGIA 30097-1502
[phone] FAX [phone]

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CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK,
DO NOT REMOVE COVER (OR BACK).
NO USER-SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
CAUTION
As this unit is intended to interface with other electrical/electronic systems, proper
engineering practices must be adhered to during installation and check-out.
All AC power and ground must be installed in accordance with National Electric
Code Standards as to conductor size and limitations (see NFPA 70, articles 200-
280, as amended, if required), and lightning protection must be provided.
All RF interconnections must be properly shielded to prevent ingression or
egression of potential interfering sources to existing services.
Any damage to this unit caused by improper wiring/interconnections will void any
warranty extended.
The following warranty applies to all Wegener Communications products.
All Wegener Communications products are warranted against defective materials and workmanship for
a period of one year after shipment to customer. Wegener Communications' obligation under this
warranty is limited to repairing or, at Wegener Communications' option, replacing parts, subassemblies,
or entire assemblies. Wegener Communications shall not be liable for any special, indirect, or
consequential damages. This warranty does not cover parts or equipment which have been subject to
misuse, negligence, or accident by the customer during use. All shipping costs for warranty repairs will
be prepaid by the customer. There are no other warranties, express or implied, except as stated
herein.
WARRANTY

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Table of Contents
SECTION 1 - GENERAL INFORMATION
Section Title Page
1.1 INTRODUCTION ............................................................................................ 9
1.2 SYSTEM DESCRIPTION ................................................................................ 9
1.2.1 System Capabilities .............................................................................. 9
1.2.2 Transmitter Characteristics .................................................................. 9
1.3 TECHNICAL SUPPORT.................................................................................. 12
1.4 FACTORY DEFAULT SETTINGS ................................................................. 13
SECTION 2 - PHYSICAL DESCRIPTION
2.1 INTRODUCTION ............................................................................................ 15
2.2 FRONT PANEL CONTROLS AND INDICATORS ....................................... 15
2.2.1 Main Keypad ........................................................................................ 15
2.2.2 Function Keypad .................................................................................. 16
2.3 REAR PANEL CONNECTORS ...................................................................... 16
2.4 INTERNAL CONSTRUCTION ....................................................................... 17
SECTION 3 - FUNCTIONAL DESCRIPTION
3.1 INTRODUCTION ............................................................................................ 19
3.2 SIGNAL PROCESSING .................................................................................. 19
3.2.1 Video Input Board ................................................................................ 19
3.2.2 Video Compression Board ................................................................... 19
3.2.3 Audio Board ......................................................................................... 19
3.2.4 Multiplexer ........................................................................................... 19
3.2.5 Modem ................................................................................................. 19
3.3 DETERMINING OVERALL BANDWIDTH ................................................. 19
3.3.1 Occupied Bandwidth (6 dB) ................................................................ 20

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Table of Contents (Continued)
SECTION 4 - INSTALLATION
Section Title Page
4.1 INTRODUCTION ............................................................................................ 23
4.2 SITE REQUIREMENTS .................................................................................. 23
4.2.1 Equipment Considerations ................................................................... 23
4.3 UNPACKING AND INSPECTION ................................................................. 24
4.4 PHYSICAL ENVIRONMENT......................................................................... 24
4.5 CONNECTIONS AND INTERFACES ........................................................... 24
4.5.1 Video Hookups ..................................................................................... 24
4.5.2 Audio Hookups..................................................................................... 24
4.5.3 Control and Monitoring Connections ................................................... 25
4.5.4 User ASYNC Data Input ...................................................................... 26
4.5.5 Data Output .......................................................................................... 27
4.6 INITIAL START-UP PROCEDURE ............................................................... 27
4.7 ADDITIONAL FILTER MATERIAL ............................................................. 28
SECTION 5- OPERATION
5.1 INTRODUCTION ............................................................................................ 29
5.2 FRONT PANEL INDICATORS ...................................................................... 29
5.2.1 Function Keypad .................................................................................. 29
5.2.2 Main Keypad ........................................................................................ 30
5.3 FRONT PANEL OPERATION ....................................................................... 30
5.4 CONFIGURING THE UNIT ............................................................................ 31
5.4.1 Configuring Audio Parameters ............................................................. 32
5.4.2 Configuring Video Parameters ............................................................. 36
5.5 CONFIGURING THE TRANSMISSION PLAN ............................................. 38
5.5.1 Allocating Rates ................................................................................... 38
5.5.2 Setting the IF Frequency ...................................................................... 41
5.5.3 Setting Encoder Number ...................................................................... 41
5.5.4 Setting Other Transmitter Parameters .................................................. 41
5.5.5 Scrambling ............................................................................................ 43
5.5.6 Using the Maintenance Menu .............................................................. 43

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Table of Contents (Continued)
Section Title Page
5.6 STARTING AND STOPPING THE UNIT ...................................................... 45
5.7 USING THE SYSTEM ..................................................................................... 45
LIST OF ILLUSTRATIONS
Figure Title Page
1 DVT2000 Digital Video Transmitter Front Panel ............................................ 10
2 DVT2000 Digital Video Transmitter Front and Rear Panels ........................... 15
3 Board Location ................................................................................................ 17
4 DVT2000 Bandwidth Requirements ................................................................ 21
5 DVT2000 System Block Diagram .................................................................... 22
6 Model DVT2000 Rear Panel Connections ....................................................... 24
7 Setup Menu ...................................................................................................... 27
8 Function Keypad .............................................................................................. 29
9Main Keypad .................................................................................................... 30
LIST OF TABLES
Table Title Page
1Model DVT2000 Digital Video Transmitter Technical Specifications ............. 11
2Main Keypad .................................................................................................... 16
3 Function Keypad .............................................................................................. 16
4Model DVT2000 Rear Panel Connections ....................................................... 18
5Audio Inputs ..................................................................................................... 25
6Audio Outputs .................................................................................................. 25
7DVT2000 Serial Cables to Printer or Terminal ................................................ 26
8DVT2000 Data Output Connector Wiring RS-422 .......................................... 27

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SECTION 1
GENERAL INFORMATION
1.1 INTRODUCTION
This manual describes the installation and operation of Wegener Communications DVT2000
Digital Video Transmitter. The transmitter is a rack-mounted unit, as shown in Figure 1. It is
normally used in conjunction with the DVR2000 receiver in satellite-based digital video
broadcast networks to transmit and receive video, audio and data.
1.2 SYSTEM DESCRIPTION
The DVT2000 Transmitter and DVR2000 Receiver comprise the DV2000 Digital Video
Transmission System. The system uses the MPEG-2 compression technique, with I, B and P
frames. At the transmit site (uplink), the DVT2000 transmitter converts analog or digital video
and audio signals to compressed digital form and transmits them over a satellite link to the
receivers. The high level of compression permits many video signals to be transmitted in the
space normally occupied by a single video signal.
At the receive site, a dish antenna with an LNB (low-noise block downconverter) recovers the
signal and converts it to the L-band frequency range (950 to 2050 MHz). This L-band signal is
carried by coaxial cable (possibly through in-line amplifiers) to the integrated DVR2000
receiver/decoder. The receiver automatically tunes to the desired signal and reconstructs the
original video and audio signals.
1.2.1 System Capabilities
The system features user-defined flexibility. Video compression can be varied between 2.5Mb/s
for low-end applications, to 15 Mb/s for sports and entertainment events. Full field/frame
compensation is possible, with variable B frames and GOP size. The system handles both NTSC
and PAL video, and analog or digital audio.
A variable rate QPSK modem with convolutional and Reed-Solomon error correction permits
users to define the optimal combination of transmission rate up to 20 Mb/s.
1.2.2 Transmitter Characteristics
The DVT2000 Digital Video Transmitter accepts analog video in composite format in NTSC or
PAL standards. The video is converted to CCIR 601 (D1) digital video for subsequent
processing. The unit also accepts D1 video directly.
The encoded multiplexed data is Forward Error Correction (FEC) coded using DVB compliant
concatenated coding. This signal is then modulated by a variable rate Quadrature Phase-Shift
Keyed (QPSK) modulator and output as a 70 MHz IF, tunable in 100 kHz steps. The transmitter

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parameters are controlled through a front panel keypad and LCD display, or remotely through an
RS-232 link. Control operations include setup and diagnostics.
Transmitter specifications are listed in Table 2.
Figure 1. DVT2000 Digital Video Transmitter Front Panel
MPEG-2 VIDEO TRANSMITTER
COMSATCOMSAT
MODEL DVT2000 7 98
4 65
1 32
DEL ENT
0
WEGENERWEGENER
COMMUNICATIONSCOMMUNICATIONS
®
ALARM
POWER
MENU LOCK RESET REM
MENU:
CONFIG.
MONITOR

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TABLE 1. DVT2000 DIGITAL VIDEO TRANSMITTER
TECHNICAL SPECIFICATIONS
TABLE 1. DVT2000 DIGITAL VIDEO TRANSMITTER
TECHNICAL SPECIFICATIONS
CHARACTERISTIC SPECIFICATION
Input
Video Analog composite NTSC/PAL; D1
Audio AES/EBU digital; Analog stereo
Encoding
Modulation QPSK
Channel FEC Concatenated:
Reed-Solomon (204/188) –
Convolutional rate 1/2, 2/3, 3/4, 5/6, 7/8
Minimum Eb/No@FEC rate 4.0dB@1/2; 4.8dB@2/3; 5.5dB@3/4;
6.1dB@5/6; 6.7dB@7/8
Video Coding ISO MPEG-2
Audio Coding ISO MPEG-1 Layer 2
Channel Spacing User configurable
Occupied Bandwidth User configurable
Information Rate User configurable
Transmit Rate User configurable
Output
IF
Frequency 70 +18 MHz; tunable in 100kHz steps
Level Adjustable from -10 to -30 dBm
Size 19"W X 17"D X 5.25"H
Weight 32 lb.
Power 90 - 240 VAC, 50 - 60 Hz, 250 Watts

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1.3 TECHNICAL SUPPORT
Should the product fail to perform as described, contact Wegener Communications Customer
Service at (770)-814-4057.
To return a product for service:
1. Obtain a Return Material Authorization (RMA) by contacting Customer Service by voice at
[phone] or by FAX at [phone].
2. Plainly write the RMA number on the outside of the product shipping container.
NOTE: Writing the RMA number on the outside of the shipping container will
help us to return your equipment to you sooner. Thank you.
3. Return the product, freight prepaid, to the address below.
Service Department RMA #_______
Wegener Communications, Inc.
11350 Technology Circle
Duluth, GA 30097
NOTE : All returned material must be shipped freight prepaid. COD shipments
will not be accepted.
Please contact Customer Service at the number above if you have any questions regarding
service procedures.

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1.4 FACTORY DEFAULT SETTINGS
The Series 2000 MPEG2 Digital video products are set to the following parameters at the factory.
Before attempting to change any of the parameters, it is mandatory that you read the instruction
manual on the products. Become familiar with the menu before making changes in the setup.
DEFAULT SETTING FOR DVT2000 MPEG-2 TRANSMITTER
FOR CONFIGURATION "O"
Info Rate 8.5 Mbits
FEC Rate 3/4
Channel 1 audio bit rate 192 kbits
Data channel bit rate 0 kbits
IF Frequency 70.00 MHz
Encoder Number 0 of 1
IF Power -10 dBm
RS Code Mode 204,188
RS Polynomial DVB
Output ON (This will display OFF when in setup mode)
Number of Audio Channels 1
Channel 1 Input Analog
Channel 1 Layer Layer II
Channel 1 Format Stereo
Channel 1 Delay 0
Channel 1 Sampling Rate 48 kbits
Channel 1 Emphasis None
Video Resolution 704 x 480
GOP (Group of Pictures) Bi-directional (IBP)
Video Standard NTSC or PAL
Video Format Composite

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SECTION 2
PHYSICAL DESCRIPTION
2.1 INTRODUCTION
This section describes the physical characteristics of the DVR2000 Digital Video Transmitter.
Front panel controls and displays are defined, and rear panel connectors described. The panels
are illustrated in Figure 2.
Figure 2. Model DVT2000 Digital Video Transmitter Front and Rear Panels
2.2 FRONT PANEL CONTROLS AND DISPLAYS
The DVT2000 transmitter may be controlled from two front panel keypads—the Main keypad
and Function keypad. An LCD display shows the control menus and keyboard input.
2.2.1 Main Keypad
The Main keypad has ten number keys, four arrow keys, and Delete and Enter keys. These are
used to enter commands and settings, and are defined in Table 2.
REF OUTREF IN
S-VideoCOMP/Y
R-Y
B-Y
GND
RIGHT
AC POWER
LEFT
A
U
D
1
A
U
D
2
A
U
D
3
IF OUTPUT
IF MONITOR
INPUT
IF MONITOR
OUTPUT
COMP VIDEO
AUDIO L AUDIO R
ANALOG INPUTMONITOR OUTPUTDIGITAL INPUT
RS-422
CONTACT CLOSURE
CONTROL
CONTROL SWITCH
ASYNC RS-232
CONTROL
SYNC RS-422
AUDIO 3AUDIO 2AUDIO 1
D1 INPUT
DIGITAL OUTPUT
MPEG-2 VIDEO TRANSMITTER
COMSATCOMSAT
MODEL DVT2000 7 98
4 65
1 32
DEL ENT
0
WEGENERWEGENER
COMMUNICATIONSCOMMUNICATIONS
®
ALARM
POWER
MENU LOCK RESET REM
MENU:
CONFIG.
MONITOR

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2.2.2 Function Keypad
The Function keypad selects the operation desired. There are four selections: Menu, Lock, Reset
and Rem(ote). These are defined in Table 3.
TABLE 2. MAIN KEYPAD
KEY DEFINITION
0-9 0-9
DEL Deletes entry
ENT Enter
↑Up
↓Down
←Left
→Right
TABLE 3. FUNCTION KEYPAD
KEY DEFINITION
Menu Selects Menu flows for
transmitter and network
control
Lock Locks the front panel
control
Reset Reboots the system
Rem Not used. Use rear control
toggle switch "down" for
remote control.
2.3 REAR PANEL CONNECTORS
All connections to the transmitter are made to the rear panel. The connectors and ports are
described in Table 4.

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2.4 INTERNAL CONSTRUCTION
The unit contains five circuit boards. These are:
•Video compression board
•Video input board
•Multiplexer board
•Audio board.
•Modem board
Board location is illustrated in Figure 3. A Quasi-VME bus provides communication between
boards.
FIGURE 3. BOARD LOCATION
Power Supply
Fans
VCOMP
Multiplexer
Video Input
Modem
Audio Codec

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TABLE 4. DVT2000 Rear Panel Connections
Signal Connector Description
DIGITAL INPUT
D1
AUDIO 1,2,3*
DATA
Async
BNC
XLR-3
RS232, DB9 Female
CCIR-601, 4:2:2
AES/EBU format
User data input
DIGITAL OUT
RS-422 DB-37, Female Compressed MPEG-2 transport stream
MONITOR OUT
Composite
Audio L, R
BNC Coax
XLR-3, Male
1 Vpp Baseband Video Signal, unmodulated video
output.
Balanced signal; max. range +9 dBm
IF
IF Output
IF Mon Output
IF Mon Input
BNC, 75S
BNC, 75S
BNC, 75S
70 MHz ±18 MHz
Future Option
ANALOG INPUT
Audio
1,2,3* L&R
Video
Ref In
Comp
XLR-3, Female
BNC
BNC
Balanced signal; max. range +9 dBm (referenced to
600 ohms)
Actual input impedance: 10K ohms
Used for GENLOCK
1 Vpp baseband
CONTACT
CLOSURE
(1,2 &3)
Major Alarm Summary
CONTROL 9 Pin D Type Remote Control of Encoder Functions
* Audio 3 optional

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SECTION 3
FUNCTIONAL DESCRIPTION
3.1 INTRODUCTION
This section describes the basic signal processing functions of the DVT2000 Digital Video
Transmitter.
3.2 SIGNAL PROCESSING
The following paragraphs explain the signal processing functions of the transmitter circuit boards.
Refer to the simplified block diagram in Figure 5.
3.2.1 Video Input Board
The Video Input Board performs analog-to-digital conversion of the selected analog video input,
sending the converted signal to the Video Compression board. Digital video is passed through.
The Video Input Board includes a built-in decoder that permits monitoring of the converted
signal, and ALSO accepts a Ref. Video input for GENLOCK operation.
3.2.2 Video Compression Board
The Video Compression Board operates at bit rates from 2.5 to 15 Mbps. It provides MPEG-2
coding of the digitized video.
3.2.3 Audio Board
The audio board accepts three pairs of audio channels with data rates selectable from 32 kbit/s to
384 kbit/s. This board also contains a decoder to permit local monitoring of the signal.
3.2.4 Multiplexer
The Multiplexer board combines the video, audio, and Auxiliary Data input into a MPEG 2
output. It also accepts data from a remote terminal in Terminal Control mode.
3.2.5 Modem
Accepts data from multiplex board and provides modulated 70 MHz output.
3.3 DETERMINING OVERALL BANDWIDTH
A transmission system has a specific bandwidth available to carry all the signals input. The rates
you set for your transmission plan combine to occupy a specific bandwidth. It is important that
the occupied bandwidth be within the bandwidth available in the system.
When you select a data rate on the front of the DVT2000 encoder, you are actually selecting the
total data rate feeding into the modulator section. In addition to the video, audio, and aux. data

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rates, it includes Reed Solomon Forward Error Correction and all MPEG transport layer
overheads. The actual data rated associated with video can be read from the front panel while
going through the initial settings of bit rate/FEC. This value can also be calculated from the
following formula:
Video Rate = (184/204) x information rate - 1.2 x (total of all audio rates) - 1.1 x aux. data rate -
192 kbitsSEC.
For example, if the DVT2000 is set for 9 Mbits/sec information rate with 2 audio channels each
at 128 kbits/sec, and an aux. data channel at 9.6 Kbits/sec, then the actual video rate is:
(184/204) x 9 - 1.2 (0.256) - 1.1 x 0.0096 - 0.192 = 7.61 Mbits/sec.
The signal feeding the modulator is at the information rate shown on the encoder. It is then
subject to the outer convolutional forward error correction at the rate specified by the user. All
standard DVB rates are available, and selection will depend upon link budget variables.
Generally if the link is power limited, a lower value of FEC code such as 1/2 or 2/3 will be
selected. If the link is bandwidth limited, then higher FEC rates such as 3/4 or 5/6 would most
likely be used.
Eb/No performance of the receiver varies as a function of FEC rate used such that best
performance is achieved with rate 1/2 FEC, and worst performance with rate 7/8 FEC/.
FEC Code Eb/No Required
Rate 1/2 4.0 dB
Rate 2/3 4.8 dB
Rate 3/4 5.5 dB
Rate 5/6 6.1dB
Rate 7/8 6.7dB
3.3.1 Occupied Bandwidth (6 dB)
Since the signal is QPSK modulated, the occupied bandwidth can easily be predicted. The chart
in Figure 4 shows the expected occupied bandwidths for the complete range of data rates and
FEC codes within the scope of this equipment. Note that the specified information rate for the
system is 2.5 to 15 Mbits/sec. Since the modulator can only operate between 2.5 and 20
Mbits/sec., the operator must be careful to avoid invalid combinations of information rate and
FEC code that would violate this specification. For example, an information rate of 15
Mbits/sec. and an FEC code of 1/2 would yield a transmitted data rate of 30 Mbits/sec., which is
beyond the modulator's capabilities. Rate 3/4 at 15 Mbits/sec., however, is a valid combination.
The chart shows predicted bandwidths for all FEC codes.