42 GC250 Technical Manual
EAAM057608EN
5.7.3
Conversion curves
The conversion curves are a tool which allow you to convert a numerical value into another
numerical value. They can be used to convert the value acquired by an analogue input of
voltage or resistance to the real measure unit of the sensor.
INFORMAZIONE!
: the conversion curves cannot be configured directly from the
panel of the controller board, but through a PC equipped with the BoardPrg3 software.
Once created, the curves can be saved on file to be reused, including on other
controllers.
The previous figure shows a hypothetical conversion/resistance/pressure curve associated to
an analogue resistive input. You can add up to 32 points in the graph, thus creating also non
linear curves. See in the example that the curve configured has two horizontal segments at
the beginning and at the end, obtained by entering two equal values in the “After” column,
corresponding to two di
fferent values in the “before” column. This is not obligatory, but it allows
you to set a saturation limit on one end or on both ends of the curve. In fact, the controller
board extends to infinity the first and last segments of the curve. Being horizontal, whatever
value the measure “to convert” assumes, you will obtain the same value of the “converted”
measure.
The BoardPrg3 software allows you (by means of the first buttons on top left) to save the curve
on file to be able to use it again in other applications. So you can create an archive of the
conversions associated to the sensors used.
5.8
The device has 4 specific digital inputs
T.16, T.17, T.18
and
T.19.
Beside them, if not used as measure inputs, it is also possible to use analogue inputs as digital
T.13
,
T.14
e
T.15
(see par.0) and, with different modes, also the terminal
T.09
(D+ signal, see
par.5.5.2). All digital inputs or inputs used as digital, are configurable.
In addition, there are
16 “virtual” inputs available, which are not really present on the controller
or on the expansions, but they are obtained as a result of the logical combination of physical
or virtual inputs, outputs, alarms or logical states by means of proper programming via
BoardPrg3. The virtual inputs can be configured as feature and can be used the same way as
the physical inputs.
