wtw Oxi 170, Operating Instructions Manual

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Overview Oxi 170
68 ba24105e08 11/2010
1.2 Outputs and interfaces
1.2.1 Overview
The monitor has the following outputs and interfaces depending on the
instrument version:
1.2.2 Freely configurable relay (RT and RT RS option)
Both potential-free K1 and K2 relays of the RT and RT RS instrument
versions can be used as follows:
z
As a fault indicator if the power fails
z
As an indicator relay for a frozen measured value (e.g. when
calibrating)
z
As a threshold indicator if a specified threshold is undercut or
exceeded (main measured value)
z
As a control relay with timer function, e.g. for time-controlled sensor
cleaning operated by compressed air.
1.2.3 SensCheck relay (sensor monitoring)
The SensCheck relay is designed as a closer (galvanically separated
from the instrument). It becomes active if a sensor error such as a hole
in the membrane cap occurs. At the same time, the SensCheck symbol
appears on the display (see section 4.1).
Instrument version Relays Current outputs Digital
interfaces
Oxi 170 (standard) 1 x SensCheck 1 x analog output for
measured D.O. value
-
Oxi 170 RT 2 additional, freely
configurable relays
1 additional analog output
for the measured
temperature value
-
Oxi 170 RT RS as RT option as RT option 1 x RS 485