Service manual

Section - VII Reagent Module BT3000 PLUS Rev. 0, Soft Ver. 8 Page 1 of 6
SECTION VII
REAGENT SYSTEM
7-1. GENERAL
The reagent module system incorporates an appropriately insulated reagent chamber (in
aluminum) for reagents refrigeration. The reagent chamber accommodates the rotating
reagent plate (divided into sectors) where trays with wedge-shaped reagent bottles are
inserted. Each reagent tray (removable) can accommodate 5 large wedge-shaped
reagent bottles (50ml or 80ml) snap-fitted with 5 smaller reagent bottles (10ml or 20ml),
for a total of 80 reagent bottles.
Two large heatsinks with eight (8) Peltier assemblies are affixed to the underside of the
reagent module. A cross-flow blower located near the heatsinks, removes the air towards
outside. An electronic circuit in feedback with temperature sensor regulates the electronic
current of Peltiers and ventilator, thus realizing the temperature monitoring system. A
stepping motor driven belt-drive/pulley mechanism provides rotary motion to the reagent
plate.
The temperature uniformity throughout the reagent chamber is maintained at
approximately 12ºC. The temperature inside the reagent chamber is maintained constant
up to 26ºC of ambient temperature. Any increase beyond this ambient temperature value
will consequently increase the reagent chamber temperature considerably.
7-2. REAGENT PLATE CONTROLLER - 15-05211-01
(Valid from July 2004 onwards)
The board 15-05211-01 is mainly dedicated to the barcode scanner, stepping motor,
temperature monitoring, and the reset sensor for the reagent plate.
It consists primarily of a µC U3 87LPC767, which controls the actuation of stepper motor
connected to the connector J3.
The stepping motor provides rotary motion to the reagent plate accommodating reagent
trays with reagent bottles. The isolation between the driver A1 (power constituent) and
the µC U3 (digital element) is obtained through the optoisolators U4 and U5 (TLP2630).
The µC U3 (with gates P1.0 and P1.1) and the integrated circuit U6 control the signals
from the barcode module connected to J5.
The Hall sensor is connected to the board through J4. The reagent plate resetting occurs
when the Hall sensor is face to face with its magnet located in the reagent pulley.
The refrigerator temperature control is accomplished through the comparator U7A
(MAX492). The voltage present at pin 1 of the comparator reaches the gate P0.4 of U3
and its value corresponding to the reagent plate temperature determines the amount of
voltage to be supplied to the Peltier and as well as turning on or off the cross blower fan.
The U7B part of the comparator is dedicated to the control of the safety interlock sensor
connected to J6. This sensor stops the plate movement when the reagent access cover is
opened.