Delta OHM HD45 17A, Manual

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4.1 Analog outputs
HD45…V…, HD45…A…, HD46…V and HD46…A models have an analog voltage or
active current output for each measured value on the instrument. The output range
default value is 0…10V (for V models) or 4…20mA (for A models), and default
correspondence between output and range is as follows:
Tab. 4.A: Default settings for analog outputs
Temperature output Humidity output CO
2
output
0V or 4mA = -20.0 °C 0V or 4mA = 0.0 % 0V or 4mA = 0
10V or 20mA = 80.0 °C 10V or 20mA = 100.0 % 10V or 20mA = 5000 ppm
Each output can be configured so as to make the output scale corresponding to a
preset range interval.
You can reverse the output operation, in order to make the output value decrease
when the measured value increases. You can also add or remove an offset to the
output minimum value in order to obtain 2…10Vdc or 0…20mA range.
For the configuration mode, see section “CONFIGURATION”.
In case of measure out of the set interval, the analog output remains fixed to
the extreme value if the measure is just a little out, and it becomes 11Vdc or
22mA if the measures is too over or under-range.
For a correct operation, please follow the load resistance specifications for the
analog outputs indicated in the technical data.
4.2 Relay outputs
HD45…R models have only one relay output, that can be associated to one of the
quantities measured by the instrument. The potential free contact output is preset
to close when the measure exceeds the threshold limit.
In HD46…R models, each quantity measured by the instrument is associated to a
relay output. Relay activation is indicated by the turning on of the corresponding LED
situated in the instrument front panel. The potential free contact output is preset to
close when the measure exceeds the threshold limit for CO
2
and humidity, and to
close when the measure falls below the threshold limit for temperature.
Thresholds and hysteresis can be configured. Relays can operate in various modes,
with one or two thresholds. Each relay output can be configured to operate differently
from the others. The relay contact can also be set to close when an error occurs
concerning a measured quantity, for example in case of a sensor fault or of an over
range measure. For the relay configuration mode, see section “CONFIGURATION”.
The employed relays are bistable, so there isn’t a rest state. In case of no power
supply, the relay contact holds its last set position.
Relay output in HD45…R models
In HD45 17…R and HD45 7B…R models, the relay is factory associated with
temperature while, in HD45 B…R , it is associated with CO
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measurement. The relay
can be used in two modes: