Service manual
38
3. ELECTRONIC SYSTEM AND FLUIDS
1. Description of the electronics of the A25 analyzer.
2. CPU Board (CIIM00006)
3. Power Supply Board (SP300 & CIIM00007)
4. Needle Board (CIIM00008)
5. Photometry Board (CIIM00009)
6. Racks Board (CIIM00010)
7. LED Board (CIIM00011)
8. Communications Board (CIIM00019)
9. Interconnection between boards
Description of the electronics of the A25 analyzer.
The electronics of the analyzer are made up of different boards located at different points in the analyzer and dedicated
to specific functions. Their different locations correspond to functionality and performance criteria for the functioning of
the analyzer.
There are 8 different boards, which correspond to:
CPU Board (CIIM00006)
Power Supply Board (SP300 & CIIM00007)
Needle Board (CIIM00008)
Photometry Board (CIIM00009)
Racks Board (CIIM00010)
LED Board (CIIM00011)
Communications Board (CIIM00019)
Varistor Board (I37008A)
3.1 CPU Board (CIIM00006)
This is the brain of the machine, containing the microprocessor (H8/3003), responsible for controlling all the components
of the machine. The board has different data storage systems using either static RAM (U21), FLASH memory (U18) or
EPROM (U20). The slot associated with the EPROM is used to check the functionality of the board and the recording of
the MONITOR program in the production phases of the analyzer. The other two memories are associated with the normal
functioning of the analyzer. The FLASH memory holds the application itself as well as different databases related to
factory settings, adjustments, state of the rotor and possible extensions to the application.
The U34 device also exists on the board. This is a logical programmable device (FPGA) dedicated to the control of
motors, mapped in register memory associated with end-of-run control, electrovalves, decoding of racks (CIIM00010),
level sensing and control of the photometry-associate board (CIIM00009).
The control of the motors acts directly on the sequencers corresponding to each of the analyzer axes
(U1,U3,U6,U8,U10,U12) and these, in turn, on the power drivers (U2,U4,U7,U9,U11,U13) to act on the motor. The sequencer-
driver pair is made up of the integrated L297 and L298. The regulation of the current of each axis can be configured by
means of a DAC that sets the current set point independently (U5). The sequencers are supplied through the U17
regulator and the drivers take their supply through the J16 connector, which corresponds to the 36V input on the CIIM00006
board.
The action on the thermostatation systems of the analyzer (needle and rotor) is carried out through H-shaped bridges
based on MOS technology (U29 and U30) and controlled directly from the microprocessor. The heating elements are
connected to J27 (needle) and J28 (rotor), respectively.
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