Teledyne T200 User Manual page 198

The core of the analyzer is a microcomputer/central processing unit (CPU) that controls
various internal processes, interprets data, makes calculations, and reports results using
specialized firmware developed by Teledyne API. It communicates with the user as well
as receives data from and issues commands to a variety of peripheral devices via a separate
printed circuit assembly onto which the CPU is mounted: the motherboard.
The motherboard is directly mounted to the inside rear panel and collects data, performs
signal conditioning duties and routes incoming and outgoing signals between the CPU and
the analyzer's other major components.
Data are generated by the sensor module which outputs an analog signal corresponding to
the amount of chemiluminescence present in the reaction cell. This signal is converted into
digital data by a unipolar, analog-to-digital converter, located on the motherboard.
A variety of sensors report the physical and operational status of the analyzer's major
components, again through the signal processing capabilities of the motherboard. These
status reports are used as data for the various concentration calculations and as trigger
events for certain warning messages and control commands issued by the CPU. This
information is stored in memory by the CPU and in most cases can be viewed by the user
via the front panel display.
The CPU issues commands via a series of relays and switches (also over the I
located on a separate printed circuit assembly, called the Relay PCA, to control the function
of key electromechanical devices such as heaters and valves. It also issues some commands
directly to the Sensor module (e.g. initiate Electric Test or Optical Test).
By controlling the state of various valves the CPU directs the flow of sample gas through
the various gas paths of the analyzer (NO measurement path; NO
Zero Path). Based on which path is active, the CPU interprets the sensor output to derive
raw data representing concentrations for NO
operational data stored in memory then calculates final concentrations for NO
NO .
2
The CPU communicates with the user and the outside world in several ways:
Through the analyzer's front panel LCD touch-screen interface
•
Through the serial I/O channels
•
• Various analog voltage and current outputs
• Several sets of Digital I/O channels
• Ethernet
196 Teledyne API T200 NO/NO
, NO and zero (dark condition), accesses the
x
/NO Analyzer with NumaView™ Software
2 x
C bus)
2
measurement path; Auto
x
, NO and
X
083730200A DCN7962