Orban OPTIMOD 8685, Operating Manual

Page: 57 / 357

OPTIMOD SURROUND PROCESSOR INSTALLATION
2-3
3. Mount the 8685 in a rack.
The 8685 requires three standard rack units (5 inches/12.7 cm).
There should be a good ground connection between the rack and the 8685 chas-
sis—check this with an ohmmeter to verify that the resistance is less than 0.5
Ω
.
It is wise to allow one rack unit of free space for ventilation above and below the
unit. Mounting the unit over large heat-producing devices (like a vacuum-tube
power amplifier) may shorten component life and is not recommended. Ambient
temperature should not exceed 45
°
C (113
°
F) when equipment is powered.
Equipment life will be extended if the unit is mounted away from sources of vi-
bration, like large blowers and is operated as cool as possible.
4. Connect inputs and outputs.
See the hookup and grounding information on the following pages.
TOPIC PAGE
AES3id Digital Inputs and Output ..............................................................2-6
HD-SDI Input and Output ............................................................................2-7
Analog Audio Output..................................................................................2-7
Wordclock/AES11id Sync Input ...................................................................2-7
Power Ground ..............................................................................................2-8
5. Connect remote control interface. (optional)
For a full listing of 8685’s extensive GPI remote control provisions, refer to
Remote Control Interface Programming on page 2-54.
Optically isolated remote control connections are terminated in a type DB-25
male connector located on the rear panel. It is wired according to
Figure 2-2 . To
select the desired function, apply a 5-12V AC or DC pulse between the appropri-
ate
REMOTE INTERFACE terminals. The (
−
) terminals can be connected together
and then connected to ground at pin 1 to create a Remote Common. A current-
l12VDC source is available on pin 25. If you use 48V, connect a 2k
Ω
±
10%, 2-watt carbon composition resistor in series with the Remote Common or
the (+) terminal to provide current limiting.
In a high-RF environment, these wires should be short and should be run
through foil-shielded cable, with the shield connected to CHASSIS GROUND at
both ends.
6. Connect tally outputs (optional)
See the schematic on page 6-42.
The 8685 supports two hardware tally outputs, which are NPN open-collector
and operate with respect to pin 1 (common). Therefore, the voltage applied to
the load (like a relay or optoisolator) must be positive. You can use the 12 VDC
source on pin 25 to drive the high side of the load, taking into account the fact
that the voltage on pin 25 is current limited by a 310
Ω
resistor.