Datcon DT9000, Operating Instructions Manual

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DT9000
8
20171205-V2
3.2. Principle of operation
Area of application DT9000 is an intrinsically safe loop-powered process
indicator. It capable of displaying linear process variables
of 4-20 mA transmitters in engineering units. The
transmitter signal may come up to zone 0 also. Due to the
function of DT9000 it can be placed in zone 1 or zone 2.
Two isolated outputs are available with different operating
modes for limit signaling or for simple control purposes.
DT9000 is housed in a moulded polycarbonate case
hauseproof to IP65 for installation in the field or on the
control panel.
Operating principle 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 and 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
makes process variables easily visible at a distance. A
label defining the appropriate engineering unit may be
attached to the right of the display.
DT9000 has two optically isolated transistor outputs for
limit signaling or for simple control purposes.
Power supply DT9000 is loop-powered from 4-20 mA signal, dropping
less than 2 V at 20 mA.