APPLIES TO FIXED QSTAR UFM (Continued)
36
i
In addition to setup variables such as flow,
QStar UFM applies the corresponding unit
that is selected in the “Units Setup” setting
and appended to the respective variable that
is displayed in a measuring window. Example:
If you selected the physical unit m³ for flow
variables, the values of the switching points
are also the parameters set in cubic meter.
Select the upper limit value for the relay. Relay will be
activated when measured value exceeds the maximum
limit.
i
Example:
A pump is operated in an applica-
tion and the discharge volume of this pump
is measured. The pump has a maximum
discharge volume of 6000 m3 /h and there is
a risk of damage to the pump when the dis
-
charge volume drops to less than 150 m3/h.
The objective is for QStar UFM to shut down
the pump as soon as the value drops below
a point at which damage to the pump can be
expected. So in that case lower limit has to be
set to 150m3/h, upper limit to 6000m3/h. Relay
will be activated if flow falls below 150m3/h or
exceeds 6000m3/h.
The physical unit cubic meter must have been
assigned to the flow variables in the physical
unit settings. The minimum activation point
must have the parameters setup.
Setup the Digital Output (transistor)
QStar UFM provides one digital output (DO). The DO
is a transistor output (open collector) and is typically
used as a counter for volume (m3) or heat (kWh). The
DO is operated in passive mode. That means a supply
voltage (10…30VDC) has to be provided externally.
Be careful not to confuse the positive (+) and
negative (-) voltage in order to avoid damage
to the flow transmitter.
CAUTION
Connecting Digital Output
Example 1:
Connect the plus terminal of evaluation unit (for ex-
ample, PCS) to the plus terminal of voltage supply.
Connect the negative terminal of evaluation unit to
the plus terminal of the DO. The negative terminal of
the DO has to be connected to the negative terminal
of external voltage supply.
QStar UFM
Example 2:
Connect a PNP transistor’s emitter to the positive
terminal of the external voltage supply. The basis of
the transistor should be connected (via a resistance)
to the positive terminal of the DO. The collector of the
transistor should be connected to the positive terminal
of evaluating unit (PCS). The negative terminal of the
evaluating unit has to be connected to the negative
terminals of the DO and the voltage supply.
QStar UFM
To enter the menu for Digital outputs:
Starting from main menu “Flow 1”:
Choose SETUP
-> COMPL SETUP -> I/O SETUP -> Digital Output.