Theory of Operation
AWG510 & AWG520 Service Manual 3-3
A30, GPIB Board. The fourth slot of the CPU Unit has the General Purpose
Interface Bus (GPIB) interface driver, which controls communication with
external devices over the parallel interface. The GPIB connector is on the rear
panel.
The GPIB Board also has the bus that sends the control signals to the Clock,
AWG, and Analog Output board.
The Connector board receives control signals for the display, floppy disk, and
front panel from the CPU Unit and sends them to each module. This board also
has the fan control circuitry.
The monitor display consists of a raster scan CRT and its driver. This receives
the sync and video signal from the CPU module. The monitor displays video on
a 17.8 cm (7 in.) CRT screen. The display resolution is 480640 pixels.
The CPU module sends instructions to and receives information from the
front-panel processor on the A20 Front Panel Board. The front-panel processor
reads the front-panel switches and potentiometers. Any changes in their settings
are reported to the processor system. The front-panel processor also turns the
LEDs on and off and generates the bell signal.
The 1.44 MB 3.5-inch floppy disk drive supports 2HD MS–DOS format.
The ASCII 101 key or JIS 106 key keyboard can be used through 6–pin
mini–DIN connector on the rear panel.
The low voltage power supply provides +5 V, +8 V, +12 V, +24 V, –2 V, –4.6 V,
and –8 V for all of the circuitry in the waveform generator. It also has an AC
inlet, fuse, and the principal POWER switch on the rear panel.
The principal POWER switch controls all power to the waveform generator
including the Low Voltage Power Supply. The ON/STBY switch, located on the
front panel, also controls all of the power to the waveform generator except for
part of the circuitry in the Low Voltage Power Supply.
Three brushless DC fans on the left (floppy disk) side provide forced air cooling
for the waveform generator The fan control circuitry on the A10/A11 Connector
board controls power to the fans sensing the temperature in the cabinet.
User Interface
(A10/A11, Connector
Board)
Monitor Display
Front Panel
(A20, Front Panel Board)
Floppy Disk Drive
Keyboard
Low VoltagePower Supply
Unit
Fan