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Microprocessor
Microprocessor IC U31, EPROM IC U25 (9180/9181: U40) and MOSTEK Real
Time Clock/RAM IC U22 form the components of the central processing system.
IC U23 Address Demultiplexer, IC U24 Programmable Array Logic (PAL) and IC
U28 provide serial data buses (9180/9181: U23, U24 and U28 not present). IC
U34 through IC U38 convert serial data to parallel data and provide printer data,
display data, solenoid valve control and peristaltic pump control. This fashion of
serial to parallel data conversion is used to prevent analyzer lock-up by peripheral
devices. The RS232 serial interface is a direct input/output from the microproces-
sor utilizing interface driver and receiver U29 and U30.
SnapPak Sensor
(9180/9181 only)
Optical detector ISO1 provides a signal indicating if the ISE SnapPak™ is in place.
This signal is fed to U41 which converts the light gate input to a digital logic output
indicating SnapPak position (IN or OUT).
4.3.2 Lamp Board
The lamp board contains the LED array used to illuminate the measuring chamber
and the interconnectors used for all solenoids, the peristaltic pump, door sensor and
sample turntable (9181 only). A ribbon cable from the SBC Board supplies the
electrical connection for each signal through connector JP6.
4.3.3 Display Board
The display board contains the LCD display, sample sensor connector and the
YES
and
NO
switches used for operation of the analyzer. Power and signal
interconnection is accomplished via a ribbon cable from the SBC board through
JP2 on the display board.
Display boards utilized in the 9181 analyzer also contain circuitry for both the
needle mechanism motor control and position sensor. The autosampler "Table
Present" signal is also buffered through U1 on this board.