Junger Audio C8840 User Manual

digital audio
modular

C8000

processing system

sync interface

features

• Standard sync module for a C8000 frame

• Internal sync @ 44.1 / 48 / 88.2 / 96kHz

• External sync auto format sensing : AES, Word Clock, Video Reference

• Video Reference :
Black Burst (NTSC or PAL)
Composite Sync (525 or 625)
Tri Level Sync (HD - 720p, 1080i, 1080p)

• Generates a Dolby-E frame sync reference that can be shifted in respect to
the defined video switching point

• Two fully redundant sync inputs

• Synchronous Word Clock output

• Front panel status indicator

• Front panel Lock A, Lock B indicator

The C8840 as the heart of a C8000 system. It synchronizes the backplane audio transport to maintain
glitch free hand over of serial audio data between the various I/O and processing modules.

For redundant operation it offers two inputs with automatic switch over. This allows the system integrator
to design a fail over system with independent feeds which may even have different reference formats
(E.g. BB and AES sync).

For Dolby E encoding inside a C8000 frame a frame sync pulse (AKA frame reference) is necessary.
The C8840 extracts such frame sync pulse from the input video reference. A circuit is provided to move
the edge of that reference in respect to the input video frame. I.e. one may align a Dolby E encoded signal
by the accuracy of a video line to the reference switching point.
If no video reference is connected the frame sync pulse will be generated from the internal sync source.

For non video applications like CD mastering or high resolution audio production the C8840 may be
synchronized to audio sample rates of 44.1, 88.21 or 96kHz. Pls. keep in mind that those sample rates
can not be used for SDI (Serial Digital Video) embedding / de-embedding.

The C8840 measures the input format and displays it via the Web GUI status display of the module.
In case of a severe sync problem, the Frame Controller can send a SNMP trap and / or activate a SNMP

GPO. A higher-ranking monitoring system may poll the status of the sync module(s) via SNMP.
Finally there is the feature to set the sync source via presets loaded by a GPI

and to get a GPO for the selected source.

C8840

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digital audio
modular

C8000

processing system

sync interface

technical specifications

Internal sync : 44.1, 48, 88.2, 96kHz
SYNC A IN / SYNC B IN : BNC, 75 Ohm

VIDEO : Black Burst, Composite Sync, Tri Level Sync

level : nominal 1V (0,5 … 2Vpp)
stability : < ±100ppm (typ. ±50ppm lt. AES 11, Grade2)
format : PAL / NTSC / HDTV
rates : 625i50 (PAL)
: 525i60 / 525i59,94 (NTSC)
: 1035i 59,94/60
: 1080i/50/59.94/60
: 720p/50/59.94/60
: 1080p/23.98/24/25/29.97/30/50/59.94/60
frame sync pulse : 25 … 30Hz ±1023 lines - generated from video reference

WCKL :

level : TTL, 1 … 5V
rates : 44,1, 48, 88.2, 96 kHz

General
Backplane connector : ref. to DIN41612, 64pin, a+b, male
Power supply : +5V DC
Consumption : approx. 300 mA
Dimensions : 3RU, 4HP, 160mm depth

general remark

For the alignment of the guard band of Dolby E encoded streams, the C8840 provides a frame sync pulse
[see VIDEO-REF at C8611 Dolby E encoder]. It must be derived from a 25 or 30fps (or their fractional
representatives) video reference. If the C8840 is set to internal sync (or falls back to internal sync), the
frame sync pulse will be generated internally. If one provides a frame rate > 30Hz it will automatically
divided by two. This maintains Dolby E encoding but the phase relationship is lost.
Due to the data rates Dolby E data frames will span over two progressive HD video frames.
Dolby recommends to use a HD synchronous black burst derived from the HD master SPG of a facility.
The consequence is that video editing / routing in respect to Dolby E encoded signals can be performed
every second frame only.

stability : < ±120ppm (typ. ±50ppm lt. AES 11, Grade 2)

AES/EBU : AES-3id

level : nom 1V (0,3 ... 1.2Vpp)
rates : 44,1, 48, 88.2, 96 kHz
stability : < ±120ppm (typ. ±50ppm lt. AES 11, Grade 2)

WCLK OUT : BNC, 75 Ohm

level : ≥2,4V @ 75 Ohm
rates : 44,1, 48, 88.2, 96 kHz
stability : typ. ±25ppm internal generator

C8840

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digital audio
modular

C8000

processing system

sync interface

installation

The C8000 frame must be switched off for installation or swapping of a sync module! Without a stable
clock, some interface modules can fall into irregular condition which could destroy parts of the circuits!

The C8840 must be installed in one of the red coloured fitting rails at rear of a C8932 frame, close to the
mains connector(s).

C8840

INIT

ADDRESS

SW1

6:
5:
4:
3:
2:
1:

Setting the CAN address of the module :

ADDRESS [0, 1, 2, 3]
16 position rotary encoder

A C8000 frame employs the CAN-bus for internal communication

and remote control purposes. For proper operation it is necessary
to assign each module its unique ID. To avoid conflicts, the
address scheme of a C8000 system must be planned with care
(see C8000 System Manual for details).

Since the sync module has a special role in a C8000 frame it

resides in a dedicated address room like the C8702 frame
controller. One may install up to four C8840 modules in a C8934
split (island) frame to support four independent services, each with
Dolby E encoding in a progressive HD format.

TERM

ON DIP

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