evertz 7700 Series User manual

7700 MultiFrame Manual
7736CD2 Dual Composite Decoder
Revision 1.0.4
TABLE OF CONTENTS
1. OVERVIEW............................................................................................................................1
1.1. FUNCTIONAL DESCRIPTION................................................................................................... 2
2. INSTALLATION.....................................................................................................................4
2.1. VIDEO IN AND OUT................................................................................................................... 4
2.2. AUDIO IN AND OUT .................................................................................................................. 5
3. SPECIFICATIONS .................................................................................................................6
3.1. ANALOG VIDEO INPUT ............................................................................................................ 6
3.2. REFERENCE VIDEO INPUT......................................................................................................6
3.3. ANALOG MONITORING VIDEO OUTPUT................................................................................ 6
3.4. SERIAL VIDEO OUTPUT........................................................................................................... 7
3.5. DECODER PERFORMANCE (SDI OUTPUTS ONLY) .............................................................. 7
3.6. ANALOG AUDIO INPUT (-A4 AND –A8 VERSIONS ONLY).................................................... 7
3.7. AES AUDIO OUTPUTS.............................................................................................................. 8
3.8. ELECTRICAL............................................................................................................................. 8
3.9. PHYSICAL.................................................................................................................................. 8
4. STATUS LEDS.......................................................................................................................9
4.1. MODULE STATUS LEDS .......................................................................................................... 9
4.2. AUDIO STATUS LEDS ............................................................................................................ 10
4.3. AUDIO BREAK-OUT CABLE (7736CD2-A8 ONLY)............................................................... 12
6. AUDIO BUFFER MANAGEMENT (+S OPTION ONLY)......................................................13
7. AUDIO LEVELS, HEADROOM, AND CLIPPING (-A4 AND –A8).......................................14
7.1. INPUT AUDIO LEVEL CALIBRATION.................................................................................... 14
8. ON SCREEN MENUS ..........................................................................................................16

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8.1. NAVIGATING THE ON SCREEN MENU SYSTEM.................................................................. 16
8.2. ON SCREEN DISPLAY – MAIN MENU ................................................................................... 16
8.3. ON SCREEN DISPLAY – CHANNEL X MENU........................................................................ 17
8.4. CONFIGURING THE VIDEO CONTROLS............................................................................... 17
8.4.1. Selects the Action to Take when Input Video is Missing ............................................... 17
8.4.2. Setting the Horizontal Phase of the Output Video – NTSC/525 Video.......................... 18
8.4.3. Setting the Horizontal Phase of the Output Video – PAL-B/625 Video ......................... 18
8.4.4. Monitoring the Horizontal Delay between the Input and Output Video.......................... 18
8.4.5. Setting the Vertical Phase of the Output Video – NTSC/525 Video .............................. 18
8.4.6. Setting the Vertical Phase of the Output Video – PAL-B/625 Video ............................. 18
8.4.7. Monitoring the Vertical Delay between the Input and Output Video.............................. 18
8.4.8. Monitoring the Audio Buffer Tracking ............................................................................ 19
8.5. CONFIGURING THE AUDIO CONTROLS (-A4 AND -A8)...................................................... 20
8.5.1. Selecting the Audio Destination Group ......................................................................... 20
8.5.2. Selecting the Audio Destination Group ......................................................................... 20
8.5.3. Additional Audio Delay .................................................................................................. 21
8.5.4. Monitoring the Audio Buffer Tracking ............................................................................ 21
8.5.5. Setting the Analog Levels.............................................................................................. 22
8.5.6. Audio Channels 1 and 2 Processing and Audio Channels3/4
Processing (-A8 version only) ....................................................................................... 22
8.6. CONFIGURING THE ANALOG VIDEO PROCESSING CONTROLS ..................................... 23
8.6.1. Removing the NTSC Setup Pedestal ............................................................................ 23
8.6.2. Line 21 Processing........................................................................................................ 24
8.6.3. Black Level .................................................................................................................... 24
8.6.4. Video Level.................................................................................................................... 24
8.6.5. Chroma Level ................................................................................................................ 24
8.6.6. Hue................................................................................................................................ 25
8.6.7. TBC Mode ..................................................................................................................... 25
8.6.8. Detail Enhancement Threshold ..................................................................................... 25
8.6.9. Detail Enhancement Level ............................................................................................ 25
8.6.10. Noise Reduction ............................................................................................................ 26
8.7. CONFIGURING THE GENLOCK CONTROLS........................................................................ 26
8.7.1. Setting the Video Standard ........................................................................................... 26
8.7.2. Genlock Source Selection ............................................................................................. 26
8.7.3. Setting the Free-Running Frequency ............................................................................ 27
8.8. UTILITIES................................................................................................................................. 27
8.8.1. Accessing Information about this Module and its Firmware .......................................... 27
8.8.2. Saving and Recalling Configurations ............................................................................ 27
8.8.2.1. Storing Configurations to the User Presets..................................................... 27
8.8.2.2. Recall Configurations from the User Presets .................................................. 28
8.8.3. Initiating a Software Upgrade ........................................................................................ 28
8.8.4. Restoring the Factory Default Configuration ................................................................. 28
9. JUMPERS............................................................................................................................ 29

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9.1. TERMINATION JUMPERS....................................................................................................... 29
9.2. SELECTING WHETHER LOCAL FAULTS WILL BE MONITORED
BY THE GLOBAL FRAME STATUS ....................................................................................... 29
9.3. CONFIGURING THE MODULE FOR FIRMWARE UPGRADES............................................. 29
9.4. SETTING THE COARSE ANALOG INPUT GAIN RANGE...................................................... 30
Figures
Figure 1-1: 7736CD2, 7736CD2-A4, 7736CD2-A8 Block Diagram ......................................................................3
Figure 2-1: 7736CD2 Rear Panels ........................................................................................................................4
Tables
Table 4-1: Audio Channel Status LEDs (-A4 Version) ........................................................................................10
Table 4-2: Audio Channel Status LEDs (-A8 version).........................................................................................11
Table 4-3: AES Audio Breakout Cable (Evertz Part # WPAES8-BNCM-6F) ......................................................12

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7736CD2 Dual Composite Decoder
Revision 1.0.4
REVISION HISTORY
REVISION DESCRIPTION DATE
0.0 Preliminary Nov 04
1.0 First pass complete. The drawings are missing. Dec 04
1.0.1 Block diagram and rear panels inserted Jan 05
Audio installation instructions added Oct 05
1.0.2 Audio present LEDs enabled Mar 06
1.0.3 Added 7736CD2-A8 May 07
1.0.4 General format clean up. May 09

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1. OVERVIEW
The 7736CD2 line of composite analog video to serial digital converters are dual broadcast quality video
decoders. The 7736CD2-A4 and the 7736CD2-A8 versions offer four (two per decoded channel) or eight
(four per decoded channel) high quality audio analog to digital converters. Faroudja 2D adaptive comb
filtering technology has been chosen so as not to introduce moving artifacts from the decoding process.
This makes it ideal for use in applications where the signal is destined to enter MPEG compressors. "The
low level of moving artifacts reduces the bit-rate required to digitally encode the signal for a given picture
quality level by up to 20%.1
Traditional adaptive and non-adaptive 2D comb filters can introduce artifacts in areas of high detail.
However, "by using adaptive processing incorporating Faroudja's patented H-logic and V-logic
interpolation algorithms to control both the comb filter itself and the narrow and wide band chroma filters,
these artifacts are substantially reduced not only on horizontal and vertical edges, but on diagonal edges
too. In this way, the chroma filters reduce chroma noise without blurring the signal at sharp transitions in
any direction”.2
In addition, control of the card is via an On-Screen Display, or remotely via VistaLINK®SNMP.
Features:
•One input BNC per channel. 75 Ohm or high-Z, jumper configurable input impedance
•Two SDI 525 or 625, 270 Mb/s component digital video output per channel WITHOUT OSD text
•EDH encoding on SDI outputs
•One composite analog video output with OSD text for card control
•One composite analog reference input (NTSC or PAL-B) on BNC. 75 Ohm or high-Z, jumper
configurable input impedance. One time base for both channels
•Video frame synchronizer (with +S option)
•Infinitely variable output phase (27MHz clock increments)
•Freeze modes: black, freeze
•Adjustable free running frequency via OSD. Both channels must be free-running to be able to adjust
frequency
•A comprehensive On-Screen display is available to configure the various features of the module
The Features of the Decoding Process:
•12 bit, 8fsc sampling of input video
•Internal processing to maintain 10 bit digital video quality
•Patented Faroudja adaptive 2D comb filtering technology
•Mode for support of non-time base corrected signals
•User configurable luma and chroma detail enhancement
•User selectable noise reduction
•Chroma AGC available, if desired
•User adjustable input video processing functions: black level, gain, hue, and saturation (when chroma
AGC is enabled)
1Faroudja Laboratories Inc, FLI2000S Data Sheet
2Faroudja Laboratories Inc, FLI2000S Data Sheet

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The Features of "-A4" and “-A8” Options:
•4 balanced analog audio inputs (two stereo pair) on 2 removable barrier strips (7736CD2-A4)
•8 balanced analog audio inputs (four stereo pair) on removable terminal strips (7736CD2-A8)
•High impedance inputs (user terminated for other impedances)
•Analog audio input levels are adjustable. Jumpers/switches set coarse input levels, fine input levels
are set by software control
•Audio delay “tracks” video delay (with +S option)
•Additional audio delay of up to 2.5 seconds
•Audio advance of up to 1 frame less 2.5 microseconds
•2 channels (1/2 group) of audio is multiplexed onto each of the outgoing digital video (7736CD2-A4)
•4 channels (one full group) of audio is multiplexed onto each of the outgoing digital video (7736CD2-
A8)
•2 unbalanced AES audio outputs using BNC’s (7736CD2-A4)
•4 unbalanced AES audio outputs using DB15 connector (7736CD2-A8)
•75Ωcoaxial (unbalanced) DARS reference input on BNC
•Loss of video modes: pass audio, mute audio
1.1. FUNCTIONAL DESCRIPTION
Composite analog video is converted to 12 bit parallel data and decoded to 4:2:2 digital component using
Faroudja™patented technology. Various video processing functions (gain, saturation, noise reduction, etc)
are performed during the decoding process.
In the 7736CD2-A4 version, the 4 channels of audio are converted from balanced analog to digital PCM.
In the 7736CD2-A8 version, 8 channels of audio are converted from balanced analog to digital PCM. The
digital audio is then delayed to match the delay experienced by the associated video in the video
synchronizer (with +S option). This delayed audio (with +S option) is formatted properly and delivered to
the user. For the 7736CD2-A4, audio is delivered as unbalanced 75 Ohm AES audio on BNC. For the
7736CD2-A8, audio is delivered as unbalanced AES on a DB15 connector. The same audio is also
embedded on the associated SDI output video.
Program video goes to a SDI parallel to serial converter.
The hardware mixes (keys) the on-screen text control information onto one of the video streams (the
stream will automatically be selected depending on which video is being controlled). This video goes
through a monitoring quality composite encoder with the OSD "burn-ins".
The CPU also gets pushbutton and toggle switch commands from the card edge controls and draws
extensive menus for configuring the operation of the card.
The following block diagrams illustrate the processing blocks.

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Figure 1-1: 7736CD2, 7736CD2-A4, 7736CD2-A8 Block Diagram

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2. Installation
The 7736CD2 modules come with a companion rear plate and occupy one or two slots in the 7700FR
frame. Figure 2-1 shows a picture of each of the rear panels. For information on mounting the rear plate
and inserting the module into the frame see section 3 of the 7700FR chapter.
The 7736CD2 cards must be inserted into slots with the correct rear panel. Some cards have physical
differences and some have functional differences; the associated labels will be misleading.
7736CD2-A4
2
4
3
2
1
1
AES OUT
1A
2A
1B
2B
MON
OUT
SDI OUT
DAR
SR
E
F
ANALOG
AUDIO IN
REF
IN
SDI OUT
Figure 2-1: 7736CD2 Rear Panels
2.1. VIDEO IN AND OUT
Connect a source of composite analog (NTSC or PAL-B) video to the BNC’s labeled ANALOG INPUT.
Connect a reference black signal to the REF BNC. Decoded video with embedded audio and EDH
encoding is available on the SDI OUT BNC’s, two for each channel. Decoded and re-encoded analog
video with control text is available on the MON OUT output BNC. If the card is not present or the power is
off, there will be nothing on any of the outputs. The card is designed to support two channels of video
decoding for video signals that are of the same format.

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2.2. AUDIO IN AND OUT
The audio versions of the CDM (-A4 and –A8) have audio paths through the card that are
delayed/synchronized with the video. The –A4 version performs A to D conversion on 4 balanced analog
inputs (1 stereo pair per video channel), delays the audio to match the associated video, and outputs 1
AES channel that is synchronous to the associated video. One half group of delayed audio is embedded
on the output video. The –A8 version performs A to D conversion on 8 balanced analog inputs (4 channels
per video), delays the audio to match the associated video, and outputs 2 AES channels that are
synchronous to the associated video. One full group of delayed audio is embedded on each video output.
The –A4 version of the CDM uses a removable terminal strip to connect audio. To connect audio, pull out
the removable terminal strip and, with a small screw driver, connect bare wires following the connections
on the rear panel. If the audio is unbalanced (single-ended), connect the ground to both the ground input
and the –ve input while the signal is connected to the +ve input. Push the terminal strip back into the rear
panel making sure there is enough slack in the cabling to not put pressure on the connector.
The –A8 version of the CDM uses a slightly different removable barrier strip to connect audio. To connect
audio, pull out the removable barrier strip and insert bare audio wires following the connections on the rear
plate. Audio wires are secured in the barrier strip with a mechanical spring force. If the audio is
unbalanced (single-ended), connect the ground to both the ground input and the –ve input while the signal
is connected to the +ve input. Push the barrier strip back into the rear panel making sure there is enough
slack in the cabling to not put pressure on the connector
48kHz unbalanced 75 Ohm AES is available on the AES OUTPUT BNCs.
The AES outputs are always synchronous to the output video. This means that the AES is
frequency/phase locked to the video with an exact relationship between the number of audio samples and
the number of output video frames. If you also need the AES channel status bits aligned with an external
source, apply a Digital Audio Reference Signal (DARS) with the reference phase information. The card will
automatically align the channel status bits when any AES input signal is detected on the DARS input.
The DARS signal MUST be locked to the same genlock reference signal that the
CDM hardware is using. Otherwise, the channel status bits will slip in phase,
which may cause downstream AES equipment to detect a problem. When in
doubt, do not apply a DARS signal.

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3. SPECIFICATIONS
3.1. ANALOG VIDEO INPUT
Standard: NTSC, SMPTE 170M
PAL, ITU624-4
Number of Inputs: 2 (one per video channel)
Connector: BNC per IEC 61169-8 Annex A
Signal Level: 1V nominal
Frequency Lock Range: ±75ppm from nominal
Input Level Control Range: ±4dB
Black Level Control Range: ±5 IRE
Chroma Level Control Range: ±20% (only available if chroma AGC enabled)
Hue Control Range: ±20 deg. (NTSC only)
Input Impedance: 75 Ohm or High impedance (jumper selectable)
Return Loss: >35dB to 10MHz
Lock up time on a hot switch: between 15 and 45 frames (may be longer with noisy signals)
3.2. REFERENCE VIDEO INPUT
Standard: NTSC, SMPTE 170M
PAL, ITU624-4
Number of Inputs: 1 (same reference used for both decoding channels)
Connector: BNC per IEC 61169-8 Annex A
Signal Level: 1V nominal
Frequency Lock Range: ±75ppm from nominal
Input Impedance: 75 Ohm or High impedance (jumper selectable)
Return Loss: >25dB to 10MHz
3.3. ANALOG MONITORING VIDEO OUTPUT
Standard: NTSC, SMPTE 170M
PAL, ITU624-4
Number of Outputs: 1
Connector: BNC per IEC 61169-8 Annex A
Signal Level: 1V nominal
Output Impedance: 75 Ohm
Return Loss: >35dB to 10MHz

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3.4. SERIAL VIDEO OUTPUT
Standard: SMPTE 259M-C – 525 or 625 line component.
Number of Outputs: 4 (2 per channel)
Connector: BNC per IEC 61169-8 Annex A
Signal Level: 800mV nominal
DC Offset: 0V ±0.5V
Rise and Fall Time: 900ps nominal
Overshoot: <10% of amplitude
Return Loss: >15dB to 270MHz
Jitter <0.09 UI (all outputs)
Embedded Audio: SMPTE 272M-A
3.5. DECODER PERFORMANCE (SDI outputs only)
Frequency Response: <±0.1dB (100kHz to 4.2MHz)
Differential Gain: <±0.5% typical
Differential Phase: <±0.2 deg. Typical
Noise Floor: < -57dBrms (Y ramp, 15kHz to 5MHz)
< -60dBrms (black video, 15kHz to 5MHz)
C/L Gain: <±0.5%
C/L Delay: <±9ns
Minimum Delay: 3.25 lines
Maximum Delay: 1 frame plus 3.25 lines
Inter-channel crosstalk: Within noise floor measurement
3.6. ANALOG AUDIO INPUT (-A4 and –A8 versions only)
Number of Inputs: 4 (2 per video channel) for –A4 version
8 (4 per video channel) for –A8 version
Type: Balanced analog audio
Connector: Removable terminal strip (-A4 version)
Removable barrier strip (-A8 version)
Input Impedance: 20kOhm minimum (differential)
Sampling Frequency: 48kHz
Signal Level: 0dBFS => 18 or 24dBu (jumper selectable)
Level Control Range: +/- 10dB
Frequency Response: +/- 0.1dB (20Hz to 20kHz) (broadcast quality)
SNR: 100dB with input at -0.5dBFS
THD+N: <0.001% (>100dB) @ 1kHz, -0.5 dB FS (rev 2)
<0.001% (>100dB) @ 20Hz to 20kHz, -0.5 dB FS (input video locked
to genlock video)
CMRR >100dB @ 1kHz

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3.7. AES AUDIO OUTPUTS
Number of Outputs: 2 for –A4 version (1 per video channel)
4 for –A8 version (2 per video channel)
Output Standard: SMPTE 276M, single ended synchronous AES
Connectors: BNC per IEC 61169-8 Annex A for –A4 version
DB15 connector for –A8 version
Resolution: 24 bits
Sampling Rate: synchronous 48kHz
Minimum I/O Delay: 2.1msec
Maximum I/O Delay: 2.5 seconds
3.8. ELECTRICAL
Voltage:
+ 12VDC
Power:
12 Watts CD2 version
21 Watts –A4 version
19 Watts –A8 version
EMI/RFI: Complies with FCC Part 15, class A and EU EMC directive
3.9. PHYSICAL
350FR: 2
7700FR-C 2
7700FR-C 2
Stand Alone Enclosure:
Dimensions:
14 “ L x 4.5 “ W x 1.9 “ H
(355 mm L x 114 mm W x 48 mm H)
Weight:
approx. 1.5 lbs. (0.7 Kg)

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4. STATUS LEDs
4.1. MODULE STATUS LEDS
7736CD2
toggle
switch
VIDEO B
PRESENT
LOCAL
FAULT
MODULE
STATUS push
button
VIDEO A
PRESENT
GENLOCK
STATUS
MODULE STATUS: This Green LED will be on when the module is operating properly.
LOCAL FAULT: This Red LED makes it easy to identify one module in a frame that is missing an
essential input or has another fault.
The LED will blink on and off if the microprocessor is not running.
The LED will be on when there is a fault in the module power supply or a user
configurable error condition exists.
VIDEO A, VIDEO B: The VIDEO Green LEDs (status for input A is the LED closest to the PCB and
status for input B is away from the PCB). These LEDs will indicate the video
presence of the composite analog inputs.
GENLOCKED: This Green LED is on solid if the user selected genlock source (either external
input or from the frame) is present and the user has turned on genlocking.
It is flashing if the user has turned on genlocking and the selected genlock
source is not present.
It will be off if the user has turned genlocking off.

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4.2. AUDIO STATUS LEDS
Four LEDs located on the lower end of the module (near the card extractor) indicate which audio channels
are present. Audio channel 1 LED is located closest to the center of the module. Analog audio (on -A4
versions) presence is determined with a silence detector. If the audio is not silent, the LED will be on.
Audio LED Colour Audio Channel Status
Off No channel 1 present.
1 Green Channel 1 present.
Off No channel 2 present.
2 Green Channel 2 present.
Off No channel 3 present.
3 Green Channel 3 present.
Off No channel 4 present.
4 Green Channel 4 present.
Table 4-1: Audio Channel Status LEDs (-A4 Version)
Eight bi-colour (Red and Green) LEDs located on the edge of the audio sub-board indicate which audio
channels are present. Audio channel 1 LED is located at the top of the sub-module. This analog audio
presence is determined based on level peaks. If the converted audio peaks rise above –60 dBFS, the
corresponding Green LED will be on. If the converted audio peaks reach above –1 dBFS, the
corresponding Red LED will also light up to indicate clipping proximity warning.
7736CD2-A8
Audio 1 Present Audio 2 Present Audio 4 Present Audio 6 Present Audio 7 Present Audio 8 Present Audio 3 Present Audio 5 Present

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Audio
LED Colour Audio Channel Status
Off No channel 1 present.
Green Channel 1 present (above –60 dBFS).
1
Red+Green Channel 1 level nears clipping (above –1 dBFS).
Off No channel 2 present.
Green Channel 2 present (above –60 dBFS).
2
Red+Green Channel 2 level nears clipping (above –1 dBFS).
Off No channel 3 present.
Green Channel 3 present (above –60 dBFS).
3
Red+Green Channel 3 level nears clipping (above –1 dBFS).
Off No channel 4 present.
Green Channel 4 present (above –60 dBFS).
4
Red+Green Channel 4 level nears clipping (above –1 dBFS).
Off No channel 5 present.
Green Channel 5 present (above –60 dBFS).
5
Red+Green Channel 5 level nears clipping (above –1 dBFS).
Off No channel 6 present.
Green Channel 6 present (above –60 dBFS).
6
Red+Green Channel 6 level nears clipping (above –1 dBFS).
Off No channel 7 present.
Green Channel 7 present (above –60 dBFS).
7
Red+Green Channel 7 level nears clipping (above –1 dBFS).
Off No channel 8 present.
Green Channel 8 present (above –60 dBFS).
8
Red+Green Channel 8 level nears clipping (above –1 dBFS).
Table 4-2: Audio Channel Status LEDs (-A8 version)

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4.3. Audio Break-Out Cable (7736CD2-A8 only)
AES audio is generated and output to a DB15 connector. The pin-out of this connector is as follows:
Break-out Cable Label Description DB-15 Pin
Reserved for future use 1
Reserved for future use 2
Reserved for future use 3
Reserved for future use 4
Reserved for future use 5
Reserved for future use 6
AES A2 Reserved for future use 7
Reserved for future use 8
AES B2 AES output 2 - unbalanced 9
AES B1 AES output 1 – unbalanced 10
AES A1 Reserved for future use 11
AES B4 AES output 4 – unbalanced 12
AES B3 AES output 3 - unbalanced 13
AES A4 Reserved for future use 14
AES A3 Reserved for future use 15
GND Ground Shell
Table 4-3: AES Audio Breakout Cable (Evertz Part # WPAES8-BNCM-6F)

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6. AUDIO BUFFER MANAGEMENT (+S OPTION ONLY)
The audio is delayed, through a large memory buffer, by the same time value as experienced by the video
through the video frame synchronizer. This is done to maintain a consistent video/audio relationship.
Unfortunately, when the video frame buffer drops or repeats frames of video, we cannot do the same with
the audio. The rate of the ingoing audio data is changed and over a period of time, the buffer is returned to
a value that matches the video. TA sample rate converter is used to change the rate of the incoming AES
on the -AES version. The 48kHz sampling clock is changed slightly from its nominal value on the analog
audio input (-A4 or –A8) version. This method is also used when video is first applied or there is a sudden
change in either the input video phase or genlock video phase.
When the audio buffer delay needs to be changed, there are two rates used; +/- 1% and +/- 30ppm.
Initially, a 1% rate change is used to quickly match the audio delay to the video delay. This correction will
only take a couple of seconds but will produce a pitch change. The pitch change will be discernable,
particularly on sustained musical notes. When the video/audio delays are close to each other and only
small corrections are required, the audio buffer will be adjusted with a rate change of 30ppm (30 Parts-
Per-Million is equivalent to 0.003%). This rate change will produce a pitch change that is near the
threshold of where a human can detect it and should not be discernable with normal content.
Unfortunately, the audio buffer management relies on a sample rate converter (-AES versions only) to
adjust the audio buffer size. This precludes the synchronization of non-PCM AES data (i.e. Dolby-E™). In
the future, a non-sample rate converter mode may be available.
Audio A to D converters and sample rate converters have inherent delays that are much longer than what
the minimum acceptable video I/O delay is. To allow the user to operate the video synchronizer with small
video delays, we will hold the audio buffer delay at its minimum value when the video is less than this
minimum.

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7. AUDIO LEVELS, HEADROOM, AND CLIPPING (-A4 and –A8)
This section contains notes to understand how both the 7736CD2-A4 and 7736CD2-A8 relates analog
audio levels, and digital audio levels.
Before you can calibrate the audio analog to digital converter, you must know a couple of system issues
specific to your application. What is your analog reference level and how much headroom do you want to
have in the digital audio signal? By adding these two values together, you will get the analog input level
that will just begin to saturate the digital word (This is the highest level that can be represented without
distortion with the digital numbers). This level is called 0dBFS (FS stands for "full scale"). For instance, if
your analog program reference level is 4dBu and you want 20dB of headroom in the "digital world", then
0dB FS will correspond to an analog level of 24dBu. Once the audio input level is calibrated, when you
apply a 4dBu analog signal, the digital level will be –20dBFS.
The SDI embedded audio, and the AES output audio are based on the digital quantized signal. Use either
digital audio output signal to calibrate the analog input levels.
7.1. INPUT AUDIO LEVEL CALIBRATION
The analog audio input circuitry has two gain control stages before the audio is digitized; a coarse range
(settable using jumpers in –A4 or miniature DIP switches in –A8), and a software (menu system) control.
One of the two coarse ranges is optimized for when peak audio levels are above 18dBu and one for levels
below. The jumpers, when not installed, allow input levels of up to 24dBu. When the jumpers are installed,
best performance is achieved when input peak levels are below 18dBu. The OSD menu system has
independent +/- 10dB audio level control of all four channels (see section 8.5.5 for OSD control details).
The following is an example calibration procedure:
1. Take your analog program reference level and add the amount of desired headroom in the digital
signal (SMPTE standard is 20dB). If this number is greater than 18dBu, then remove the 8 jumpers
near the rear of the 7736CD2-A4 module (on 7736CD2-A8 you would slide coarse range switches
as pointed by +24dBu arrow on the module). If the number is less than 18dBu, then install the 8
jumpers (on 7736CD2-A8, slide coarse range switches as pointed by +18dBu arrow).
2. Apply an analog audio signal of the level calculated above (maximum peak level).
3. Apply composite analog video to the "ANALOG IN" BNC.
4. Monitor either the embedded audio or the output AES audio with appropriate level measuring gear.
5. Adjust the level adjust controls in the audio menu so that the digital level just starts to clip.
6. Verify by applying program reference level. The output level should read at the desired reference
level.

7700 MultiFrame Manual
7736CD2 Dual Composite Decoder
Revision 1.0.4 Page - 15
More information:
With (the common North American) +24 dBu coarse range setting in place and 0 dB gain control, the
conversion will transform +24 dBu analog input to 0 dBFS digital signal. Gain control will allow adjustment
of this setting +/-10 dB in 0.5 dB increments (see section 8.5.5 for OSD control details). The user has to
be aware that the front-end analog amps will saturate (clip) at +27 dBu independently of adjustable fine
gain/attenuation stage and the ADC stage.
With "+18 dBu" coarse range setting in place and 0 dB gain control, the conversion will transform +18 dBu
analog input to 0 dBFS digital signal. Gain control will allow adjustment of this setting +/-10 dB in 0.5 dB
increments (see section 8.5.5 for OSD control details). The user has to be aware that the front-end analog
amps will saturate (clip) at +21 dBu independently of adjustable fine gain/attenuation stage and the ADC
stage.

7700 MultiFrame Manual
7736CD2 Dual Composite Decoder
Page - 16 Revision 1.0.4
8. ON SCREEN MENUS
8.1. NAVIGATING THE ON SCREEN MENU SYSTEM
A toggle switch and pushbutton allows card edge navigation of a set of On-Screen menus used to
configure the card. On-Screen menus are available only on the MONITOR output for the 7736CD2 series
of cards to ensure that On-Screen menus are not accidentally put on-air.
To enter the On-Screen menu system, press the pushbutton once. This will bring you to the main setup
menu where you can use the toggle switch to move up and down the list of available sub-menus. An arrow
(>) moves up and down the left hand side of the menu items to indicate which item you are currently
choosing. Once the arrow is on the desired item, press the pushbutton to select the next menu level.
On all menus, there are two extra selectable items: Back and Exit. Selecting Back will take you to the
previous menu (the one that was used to get into the current menu) while Exit will return the display to its
normal operating mode. On the main menu, BACK and EXIT will both take you to the normal operating
mode.
Once in a sub-menu, there may be another menu layer, or there may be a list of parameters to adjust. If
there is another set of menu options, use the toggle switch to select the desired menu item and press the
pushbutton.
To adjust any parameter, use the toggle switch to move up or down to the desired parameter and press
the pushbutton. The arrow will move to the right hand side of the line (<) indicating that you can now
adjust the parameter. Using the toggle switch, adjust the parameter to its desired value. If the parameter
is a numerical value, the number will increase if you lift the toggle switch and decrease if you push down
on the toggle switch. If the parameter contains a list of options, you can cycle through the list by pressing
the toggle switch in either direction.
When you have stopped at the desired value, depress the pushbutton. This will update the parameter to
the selected value and move the arrow back to the left side of the parameter list (>). Continue selecting
and adjusting other parameters or use the BACK or EXIT commands.
8.2. ON SCREEN DISPLAY – MAIN MENU
Channel 1 Configuration of the parameters associated with channel 1 video and audio.
Channel 2 Configuration of the parameters associated with channel 2 video and audio.
Genlock Configures genlocking items that are shared between channels.
Utilities Card preset management, upgrading and various debug and maintenance
features.
Video 1 = Status of channel 1.
Video 2 = Status of channel 2.
Genlock = Status of genlock input.