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Truth table notation, State diagram notation, Stc-2000a states and events – INFICON STC-2000A Thin Film Deposition Controller Operating Manual User Manual

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STC-2000A DEPOSITION CONTROLLER

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Truth Table Notation


When using Boolean operators, it is common to use a truth table, (Refer to Table 5.3). This shows

all possible combinations of inputs and the resulting outputs. Let's assume that we have 2 input terms
called A and B, and the output term is called C. The operator symbols for 'AND', 'OR' and 'NOT' are

&

,

¦,

and

!

, respectively. For the following table, we will use TRUE (T) and FALSE (F) to indicate Boolean

states.

& (AND)

¦ (OR)

! (NOT)

A & B = C

A ¦ B = C

! A = C

T T T

T F F

T T T

T F

T F T

F T

F T F

F F F

F T T

F F F

Table 5.3: Truth Table.

SECTION 5.3

STC-2000A States and Events

You are already familiar with states of the STC-2000A. Some of them appear on the RunTime

screen and appear as large characters. Common states are STOPPED, DEPOSIT, RISE 1, etc. States are
just a period of time in which the STC-2000A does a particular task. There are many internal states into
which you have access with the I/O program. It is not necessary to fully understand the internal workings
of the STC-2000A in order to write an I/O program, however. By examining the examples later in this
section, you can get a good idea of what is needed.

State Diagram Notation


In writing an I/O program, you can test whether a state is active or not. Events cause something to

happen in the STC-2000A. An example of an event is pushing the START key. In state diagram
notation
, events are the lines connecting states together. The I/O system can force events in the STC-
2000A. Refer to Table 5.4, a list of all of the states and events the I/O system can access. You may want
to copy this table and keep it handy as you go through the examples. It provides a key to the codes in an
I/O program. Four front panel LEDs (output) and four fixed front panel keys (input) have been assigned
ID's which allow them to be incorporated into an I/O program

(Table 5.6,#64-71)

.

SECTION 5.XX

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