Chapter 2
SQM-242 CoDep
2-1
2.0 Introduction
The SQM-242 CoDep program illustrates most of the capabilities of the SQM-242 card.
It is intended as a learning tool for new users, and a programming example for
interfacing to user applications. However, it is also a deceptively powerful, deposition
monitor and controller.
2.1 Main Screen
With no cards installed (or with two SQM-242 cards and an SAM-242 card installed) you
will see the display below. The number of “output frames” shown on the display will
change depending on the number of cards installed in your system. For example, with
only one SQM-242 card installed, the main display shows only two output frames.
Each output frame corresponds to a physical output on an SQM-242 card. On the
screen above, the first three outputs are each configured to use quartz sensors to
measure rate and thickness.
The frame labeled “Gas Flow” is a little different. This output uses an analog input on
the SAM-242 card to control backfill gas. The SAM-242 card can use any analog
voltage for control. More about this feature later.
Output A1 above is turned off, while Output A2 is used as a recorder output.
The output labels are easily edited to provide descriptive names. Displays within in
each output frame will change, depending on the function of that output.
