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Logical Functions and Timers [600]
11-6 Logical Functions and Timers [600]
11-6-1 Comparators [610]
With the Comparators, Logic Functions and Timers, conditional signals can
be programmed for control or signalling features. This gives you the ability to
compare different signals and values in order to generate monitoring/control-
ling features.
The comparators available make it possible to monitor different internal sig-
nals and values, and visualize via digital output or a contact, when a specific
value or status is reached or established.
Analog comparators [611]-[614]
There are 4 analogue comparators that compare any available analogue
value (including the analogue reference inputs) with two adjustable levels.The
two levels available are Level HI and Level LO. there are two analogue com-
parator types selectable, an analogue comparator with hysteresis and an ana-
logue window comparator.
The analogue hysteresis type compararator uses the two available levels to
create a hysteresis for the comparator between setting and resetting the out-
put. This function gives a clear diference in switching levels, which lets the
process adapt until a certain action is started. With such a hysteresis, even an
unstable analogue signal can be monitored without getting a nervous compar-
ator output signal. Another feature is the possibility to get a fixed indication
that a certain level has been passed. The comparator can latch by setting
Level LO to a higher value than Level HI.
The analogue window comparator uses the two available levels to define the
window in which the analogue value should be within for setting the compara-
tor output.
The input analogue value of the comparator can also be selected as bipolar,
i.e. treated as signed value or unipolar, i.e. treated as absolute value.
Digital comparators [615]
There are 4 digital comparators that compare any available digital signal.
The output signals of these comparators can be logically tied together to yield
a logical output signal.
All the output signals can be programmed to the digital or relay outputs or
used as a source for the virtual connections [560].
CA1 Setup [6111]
Analaog comparator 1, parameter group.
Analog comparator 1, Value [6111]
Selection of the analogue value for Analogue Comparator 1 (CA1).
Analogue comparator 1 compares the selectable analogue value in menu
[61111] with the constant Level HI in menu [6112] and constant Level LO in
menu [6113]. If Bipolar type [6115] input signal is selected then the compari-
son is made with sign otherwise if unipolar is selected then comparison is
made with absolute values.
For Hysteresis comparartor type [6114], when the value exceeds the upper
limit level high, the output signal CA1 is set high and !A1 low, see Fig. 101.
When the value decreases below the lower limit, the output signal CA1 is set
low and !A1 high.
The output signal can be programmed as a virtual connection source and to
the digital or relay outputs.
Section 11-6
215
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