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089770000 Rev 05
Teledyne API N500 CAPS NO
X
Analyzer with NumaView™ Software
91
ELECTRONIC OPERATION
The electronic platform is based on a Controller Area Network (CAN) bus modular
system. CAN is the central networking system that enables communication among all the
parts and facilitates centralized diagnoses of errors, as well as configuration of all the
parts. CAN bus technology allows for a uniform cable architecture with interchangeable
6-pin connectors configured for power (5 V and 24 V) and communications (CAN high
and CAN low serial lines).
The Mainboard is the main hub, which not only contains the Central Processing Unit
(CPU) that communicates with other modules, but also directs power and communication
distribution. The Mainboard includes an altitude sensor, a temperature sensor, and the
Supervisory Chip.
The Supervisory Chip monitors power and the sensors, and when the front panel Soft
Power switch is pressed (see Power Switches, Section 6.2.2), the Supervisory Chip
directs the soft power down of the internal components, to safely shut down processes
and close connections to prevent damage.
MODULES
Each module consists of its own board controlled by a microprocessor that receives
messages from and sends information to the Mainboard on the CAN network. Depending
on the signal line, CAN Low or CAN High, the modules can determine whether a
message is intended for them and what the priority is, and then act on the applicable
messages. These are called “Smart Modules,” which conduct local operations, such as
activating the zero/span valves, toggling the ozone valve, or controlling manifold
temperature. There is also the Sensor Module; it is comprised of the Bench Unit which
has the gas sensor and oven on the inside and the CAPS data acquisition (DAQ) board
with logic device, microcontroller and LED driver mounted on the outside. The Sensor
Module calculates gas concentrations and may command the Smart Modules.
POWER SWITCHES
The front panel Soft Power switch is used between hard-power on and off to protect the
internal components from damage:
•
After hard-power on, pressing and momentarily holding the blinking Soft Power
switch (indicating that the internal components are in deep sleep mode) tells the
Supervisory Chip to spin up the internal computer components and place them in
operational mode (indicated by LED’s solid-lit state).
•
Before hard-power off, pressing the solid-lit Soft Power switch tells the
Supervisory Chip to put the internal computer components through a soft-
shutdown process and into deep sleep mode (indicated by LED’s blinking state).
The rear panel Hard Power switch is used to turn on and off all power to the entire
instrument; the instrument should never be powered off until all internal computer
components have been placed in deep sleep mode through the front panel Soft Power
switch whose status LED should be blinking.
Содержание N500
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