Orban OPTIMOD-AM 9300, Руководство по эксплуатации

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OPTIMOD-AM DIGITAL TECHNICAL DATA
6-5
A block diagram of the DSP signal processing appears on page 6-41.
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 pan-
el RS-232 port, Ethernet port, and the remote contact closures. These changes affect
hardware function and/or DSP processing. The control circuits also send information
to the LCD display, the LED bar graphs, and the control status indicators.
The control circuit communicates with the DSP and display circuitry through the
SC520’s General Purpose 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 9300 has rebooted for some reason. (Of course, it
could also be caused by the 9300’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 contains interface circuitry, the CPU, the Ethernet interface chip,
the flash memory, the DRAM, the RS-232 serial interface circuitry, the GPI/O interface
circuitry, and the real-time clock, which keeps time for the 9300’s automation func-
tions. The real-time clock is backed up by a DL2032 battery so that it keeps accurate
time even when the 9300 is powered down. The battery is socketed and can be
readily accessed by removing the 9300’s top cover; the battery is located on the con-
trol board.
User Control Interface and LCD Display Circuits
The user control interface enables the user to control the 9300’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 9300. 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.