CMU Instrument Design and Function Description
1100.4903.82 3.5 E-4
FRONT MODULE
The FRONT MODULE consists of an aluminum case panel and a mounting plate which accommodates
the LCD, the keyboard mat with the membrane and the spinwheel.
The case panel incorporates the FRONT MODULE CONTROLLER, the fan and the hard disk.
LCD
The color LCD provides a visible output of any information,
measurements etc. to the user.
The resolution of the LCD is 640 * 480 pixels (VGA).
The display incorporates two cold cathode tubes for the illumination.
The high voltage required for this purpose is generated in an extra
DC/AC converter mounted next to the display on the mounting plate
and connected both to the display and the controller board via a cable.
The liquid crystal display is controlled via a ribbon cable that is plugged
in on the controller board.
Operating keys
The operating keys consisting of a keyboard mat and a membrane
release a contact when the rubber key is pressed. Two LEDs for the
STANDBY/ON key (orange for STANDBY/green for ON) are also
accommodated on this membrane.
The rubber keys enable the user to call up all CMU functions.
The key evaluation and LED control are effected via a film cable
connector on the controller board. Like the control of the two LEDs, it is
controlled in a special microprocessor on the controller board by
means of a matrix technique. This microprocessor permits to store the
status of the STANDBY/ON key when switching off using the power
switch.
Spinwheel
The spinwheel consists of a flexible magnetic ring with individual
magnets for the lock-in positions. With each turn of the spinwheel,
electrical pulses are released from the LEDs and the optical position
detectors and sent via a ribbon cable to the microprocessor on the
FRONT MODULE CONTROLLER for evaluation.
The spinwheel serves the user as a further means of data entry and
operation.
FRONT MODULE
CONTROLLER
The FRONT MODULE CONTROLLER contains all the necessary
components on a board such as processor, memory chips, I/O devices
(ISA bus), lithium battery, IEC-bus controller (IEEE), two serial
interfaces (COM1/2), a parallel interface (LPT), LCD graphics
controller, external VGA monitor graphics interface (monitor) and an
external keyboard connection (keyboard PS/2).
In addition, a floppy controller for an external floppy disk drive and an
IDE hard disk controller are integrated on the controller board.
Hard disk
The hard disk is screwed to the printed circuit board above the FRONT
MODULE CONTROLLER (MODEL 04) or is screwed to the rear of the
aluminum case panel (MODEL 12) and connected to the printed circuit
board via a ribbon cable.
Fan
A small axial fan in the case panel produces an air flow through the
FRONT MODULE CONTROLLER, cooling it with cold ambient air.
Connection
The FRONT MODULE is directly plugged to the MOTHERBOARD via
two 96-pin FUTURE BUS connectors (MODEL 04) and one additional
110-pin PCI Bus connector (MODEL 12).