Software - Abbott VP 2000 Service Manual

Section 3

Software

Abbott VP 2000™ Processor Service Manual
30-608308/R1—September 2008
All functions and operations of the Abbott VP 2000 Processor
are controlled by the system computer. These include:
• Controlling the motors
• Reading the position sensors and hood interlocks
• Controlling the Dryer Blower and Drying Temperature
• Controlling the Recirculation Pump
• Performing various built in tests
• Controlling the heated basin temperatures
These are discussed briefly below.
Software Structure
The unit software is based on a "state and event" approach. A
state is any operating configuration of the slide stainer; for
example, being stopped because the Pause button was pressed
or sitting in Bath 2 with the Agitate light ON. Each state
responds to a stimulus differently. A stimulus might be
someone pressing a key or opening the hood.
Every state stimulus has been identified; the reaction of the
unit to a stimulus is determined by a chart called a state and
event chart. The program looks at the state, checks for a
stimulus, and responds according to the state and event chart.
There are some stimuli that need to be reacted to in every
state. The Flow, Recirculate, and Soak push buttons are
examples of these. To speed up and simplify the programs,
these are not given official states, but are evaluated using
either a technique called polling or using interrupts. Polled
stimuli are checked continuously in a big loop. Whenever a
specific stimulus occurs, the reaction is same regardless of the
state of the slide stainer. Interrupts can actually interrupt the
computer from whatever it is doing, get handled, and then let
the computer go back to whatever it was doing. This is why
you can always press the Recirculate button and it works, but
most of the others only work at selected times, or states.
Theory of Operation
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