Milnor C4A, Manual, Page: 30 / 36

MSFD0503AE/9274AV (1 of 2)
È THE HARDWARE IN C4A ELECTRONIC COIN
WASHER-EXTRACTOR CONTROLS
Ê General
The MILNOR
®
C4A microprocessor control is designed specifically for MILNOR machines. Along with
certain external electromechanical relay logic and sensing devices, they control all machine and system functions.
Not every microprocessor includes all the following components.
Ê The Microprocessor Components
Ë 1. Keyswitches
—The RUN/ATTENDANT keyswitch and the RUN/TEST keyswitch allow access to the
RUN and TEST modes only by authorized personnel. The RUN/ATTENDANT key may be removed only in RUN,
and the RUN/TEST key may be removed only in RUN. Never leave keys accessible to unauthorized personnel.
Ë 2. Display
—The display is light emitting diode (LED).
Ë 3. Power Supply
—Converts control circuit AC voltage to +12VDC, -12VDC, and +5VDC for the CPU board.
The power supply is auto switchable between 120VAC and 240VAC.
Although the +12VDC and -12VDC are not adjustable, the +5VDC is rather sensitive and the power supply
must be adjusted most accurately, so that the actual voltage at the Power Supply and at the CPU board is
between 5.04 VDC and 5.06VDC as measured by an accurate digital voltmeter; otherwise the machine will
likely malfunction.
Ë 4. CPU Processor Board
—The Central Processing Unit (CPU) processes data received from the various
inputs, stores information, and responds to each pushbutton entry with the appropriate action. Data is stored in three
microprocessor chips, which reside on the CPU.
E-PROM—contains fixed instructions programmed by MILNOR
®
(software) that determine how the
machine functions. Also contains the standard formulas for all industries.
S-RAM—stores the accumulator (formula count) data so long as the machine has power, or via a capacitor
for approximately 48 hours with power off. Also stores where machine was last when power is turned off at
machine.