DSA 3217/3218 Series Modules
The DSA 3200 Series Modules require no special maintenance. The modules are tested extensively prior
to shipment. Many of the components used in the DSA 3200 Series are the same as, or derived from,
components currently on use in existing modules. The Isolate-Purge Valves have been tested in excess of
one million cycles.
Circuit Boards
All of the circuit boards in the DSA 3200 Series are multi layer boards using surface mount technology. The
Digital Sensor Array contains 4 circuit boards:
Excitation Board
The Excitation Board is the same board that is used in ZOC 17 and ZOC 16TC modules with one difference.
Besides a 1.5ma constant excitation current for each sensor, It also outputs a signal proportional to the
sensor bridge resistance. This signal is used to determine the temperature of each sensor and ultimately
the temperature plane to be used for Engineering Unit conversions.
Processor Board
The Processor Board is the heart of the module. All of the software and module intelligence resides in this
board. It uses a Hitachi RISC processor.
Power Supply Board
The power supply is a DC to DC converter which converts the +24 Vdc input voltage to +5 Vdc and ±15 Vdc
outputs.
Analog to Digital Converter Board
This board is used to convert the analog signals from the sensors to a digital signal .
Calibration Valves
The calibration valves are included so a customer can perform a calibration or a data validity check. The
valves do not require any special maintenance by a user. They should not be disassembled by a user that
has not completed training at the Scanivalve Factory.
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