Orban Optimod-TV 8382, Operating Manual

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OPTIMOD-TV DIGITAL TECHNICAL DATA
6-5
Control Circuits
The control circuit is based on an AMD Elan SC520 microprocessor, which is a 586-
class processor running an Orban executable program over a third-party real-time
operating system. A flash memory emulates a hard drive. The memory is non-volatile
and does not rely on a battery to retain information when mains power is off.
The flash memory holds the operating system, the Orban executable program, and
all preset files, both factory and user. It also contains a write-protected “boot seg-
ment” that functions as a boot ROM.
The control circuits process and execute user-initiated requests to the system. The
source of these requests is the front panel buttons and rotary encoder, the rear
panel RS-232 port, Ethernet port, and the remote contact closures. These changes
affect hardware function and/or DSP processing. The control circuits also send in-
formation to the LCD display.
The control circuit communicates with the DSP and display circuitry through the
SC520’s ISA bus.
The SC520 periodically refreshes a watchdog timer. If the timer times out without
being refreshed, it assumes that the control program has crashed and automatically
reboots the SC520. The DSP chips will continue to process audio until the time comes
to reload DSP program code into them. At this point, the audio will mute for about
a second until the DSP code download has finished. If you hear a short audio mute
on air, this may be because the 8382 has rebooted for some reason. (Of course, it
could also be caused by the 8382’s audio feed’s being interrupted.) Be prepared to
convey this fact to Orban customer service if you call for technical assistance.
The control board is divided into two assemblies: a “base board,” which has inter-
face circuitry, and a “CPU controller module,” which plugs into the base board and
which contains the CPU, the Ethernet interface chip, the flash memory, the DRAM,
and the real-time clock, which keeps time for the 8382’s automation functions. The
real-time clock is backed up by a DL2032 battery so that it keeps accurate time even
when the 8382 is powered down. The battery is socketed and can be readily ac-
cessed by removing the 8382’s top cover; the battery is located on the foil (top) side
of the CPU controller module.
User Control Interface and LCD Display Circuits
The user control interface enables the user to control the 8382’s functionality. A rear
panel GPI connector allows optically isolated remote control of certain functions,
such as recalling presets, via contact closure. An RS-232 serial port and an Ethernet
port allow you to connect a modem or computer to the 8382. Front panel pushbut-
ton switches select between various operational modes and functions. A rotary en-
coder allows the user to adjust parameters and enter data.