Chapter 8 logic statement set-up, 1 logic statement overview, Chapter 8 – INFICON Cygnus 2 Thin Film Deposition Controller User Manual
Page 131: Pter 8, logic statement set-up
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Cygnus 2 Operating Manual
Chapter 8
Logic Statement Set-Up
8.1 Logic Statement Overview
The Cygnus 2 programmable logic capabilities allow it to respond to digital external
inputs to control the execution of a Material or series of Materials without operator
intervention. You can tailor these capabilities by programming the logic statements.
A logic statement consists of an IF part and a THEN part. The IF part consists of
one or more conditional events selected from a table. IF parts can be based on
external inputs or internal system conditions or a combination of both. The THEN
part similarly consists of one or more actions selected from another table. When
the event string is determined to be true, the associated actions are executed in left
to right order. The state of the Logic statement is indicated on the Logic Overview
display and on logic statement group pages. The color of the logic statement
number will turn green to indicate the IF part of the statement is true. Also, three
stars (***) will be present. The expressions are evaluated in numerical sequence
starting with logic statement 1.
Programming is accessed by moving the cursor to the Logic heading of the
main menu and pressing MENU.
Single or multiple actions may be triggered by inputs or the fulfillment of a user
specified logical condition.
Inputs are only processed when they or the statement they are used in undergo
a transition and on Cygnus 2 power-up.
Single or multiple complex defined conditions are used to define an event.
The Logical operators; AND, OR, and NOT (negate) as well as grouping
operators (parentheses) are available to define very precise conditionality. An
additional operator, ON, specifically ties certain events together.
It is possible to execute an action immediately or delay it for a definable period
of time through use of a timer or a counter.
Each Logic statement is evaluated every measurement cycle of 100 ms, but
evaluation is suspended while a configuration file is being loaded.
Material entries for each logic statement can be made exclusive or inclusive.
The components of the Logic statements may be the transition between or
entry of a specific state, specific programmable time limits, programmable
thickness limits or various error conditions.
There are user defined messages which may be displayed.