Mechanical
Main computer, display unit and printer take 3 standard radio cassette locations
in the drivers panel. Measurement computer is placed in a small metal box (200
x 150 x 80 mm) in the trunk.
Main computer
H64180 microprocessor from Hitachi with 64 kB EPROM and 32 kB RAM with lithium
back-up battery. The RAM area can be extended to 64 kB. Real time clock with
built-in battery. Function supervision with watchdog if any uncontrolled situation
should arise. Tests are performed on-line to check all subsystems. Piezoelectric
summer. Interfaces for RS-485 2-wire communication, keyboard (panel), display,
printer opto isolated inputs and 8 relay functions.
Measurement computer
80C552 micro processor with 8 kB EPROM and 256 B RAM. Input/output: 8 multiplexed
channels of 10-bit A/D converters. Interfaces for input voltage signal from
strain gauge in chain transmission, input current signal from pressure transducer.
Input pulses from transmitter at wheel axle (opto isolated) and series link
with main computer RS-485 2-wire communication.
Display unit
LCD graphic display with 32 x 120 pixels. Text can be displayed as 4 lines of
20 characters. Backlight of LED type.
Keyboard
Illuminated keys for POWER ON, positioning (LEFT, RIGHT, UP and DOWN) and operations
(ACCEPT and CANCEL).
Printer
Thermal strip printer using Seiko LTP3245 mechanism incorporated in an electronic
unit GeBe GCT-3282. Density is 384 dots per line (24 characters) and maximum
paper speed is 20 mm/second.