Milnor E-P Plus, Справочник, Страница: 83 / 92

Pellerin Milnor Corporation
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Although the +12VDC and –12VDC are not adjustable, the +5VDC is rather sensitive and the
power supply must be adjusted so
the actual voltage at the processor board is between
5.04VDC and 5.06VDC as measured by an accurate digital voltmeter. If this voltage is not within
the stated range, the machine may malfunction.
5.1.4 CPU Processor Board
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The central processing unit (CPU) processes data received from the various inputs, stores infor-
mation, and responds to each push button entry with the appropriate action. Data is stored in one
or more of the following types of memory chips on the CPU board, depending on the machine
model.
SRAM Static Random Access Memory
stores the accumulator (formula count) data as long
as the machine has power, or via a capacitor for approximately 24 hours with power off. This
type of component is also used to retain the last formula and step in progress when power is
turned off at the machine while a formula is running. SRAM is used in all E-P Plus
®
and E-P
Express ® controllers.
Flash Memory Similar to EEPROM memory in function, flash memory can be electrically
erased and reprogrammed, but is faster and can retain more data than EEPROM memory.
Flash memory is used on processor boards for F_J, H_J, X_J, and V_J models, and all E-P
Express
® models. The two flash memory chips reside in sockets IC2 and IC12. The chip in
socket IC12 contains operating instructions and the complete set of industry standard formu-
las. As software updates are made available, the owner/operator may choose to replace this
chip. The chip in socket IC2 holds the industry formulas and user changes to those formulas,
as well as machine configuration data. The chip in socket IC2 will not normally need replac-
ing for software updates.
5.1.5 Outputs
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Depending on the processor board, output relays may be either socket-mounted to a separate out-
put board, or permanently soldered to the processor board. H_J, F_J, V_J, and X_J models, as
well as all E-P Express
® models, use the 188 processor board with soldered relays. The SPST
(single pole, single throw) relays have the same load parameters as those used in other models
(25VA).
WARNING:
Avoid damage to electronic boards — Although the relays on 188 pro-
cessor boards are capable of handling higher loads, failure to restrict cur-
rent loads to the values stated above may cause traces on the processor
board to fail, thus destroying the board.
Supplemental Information