Principle Of Operation - Datcon DT9002 Operating Instructions Manual

Area of application
Operating principle
Power supply
8

3.2. Principle of operation

DT9002 is an intrinsically safe process indicator enable
linear process variables to be displayed in engineering units
in even the most hazardous plant areas: Zone 1, 2 or in the
safe area. Two isolated outputs are available with different
operating modes for limit signaling or for simple control
purposes.
DT9002 is housed in a DIN standard 144 x 72 mm ABS
case with IP 65 protection from the front and IP 30
protection from the back side, for installation on the control
panel.
The 4-20 mA current flows through a measuring resistor
and is converted by a 16 bit A/D converter into digital value.
The digital value is processed by a microcontroller. The user
may set up the the configuration parameters: scaling,
decimal point position, display refresh rate, signal filtering,
limit modes, limit values, etc. through the front panel
membrane keypad. The parameters stored in EEPROM. A
two level password protects the settings from unauthorised
changes.
Large 4 ½-digit, 20.5 mm height liquid crystal display make
process variables easily visible at a distance. A label
defining the appropriate engineering unit may be attached
to the right of the display.
DT9002 has two optically isolated transistor outputs for limit
signaling or for simple control purposes.
DT9002 is loop-powered from 4-20 mA signal, dropping less
than 2 V at 20 mA.
DT9002
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