Digital Input; External Setpoint Signal - Grundfos CRE Serie Notice D'installation Et De Fonctionnement

4.7 Digital input

By means of the R100, one of the following functions can be
selected for the digital input:
• Normal duty
• Min. curve
• Max. curve
• External fault
• Flow switch
• Dry running.
Functional diagram: Input for digital function
Digital function
(terminals 1 and 9) (terminals 9 and 10) (terminals 9 and 11)
H
H
H
H
5 s
delay
H
5 s
5 s
delay
H

4.8 External setpoint signal

The setpoint can be remote-set by connecting an analogue signal
transmitter to the input for the setpoint signal (terminal 4).
Setpoint
External setpoint
Fig. 24 Actual setpoint as a product (multiplied value) of
setpoint and external setpoint
Select the actual external signal, 0-10 V, 0-20 mA, 4-20 mA, via
the R100. See section 4.4.3 External setpoint.
If control mode uncontrolled is selected by means of the R100,
the pump can be controlled by any controller.
In control mode controlled, the setpoint can be set externally
within the range from the lower value of the sensor measuring
range to the setpoint set on the pump or by means of the R100.
Normal duty
Q
Min. curve
Q
Max. curve
Q
External fault
Q
Flow switch
Q
Dry running
Q
Actual setpoint
Actual setpoint
Sensor
Setpoint set by means of
control panel, R100 or PC Tool
E-products
Actual
setpoint
Sensor
0 10 V
0 20 mA
4 20 mA
Fig. 25 Relation between the actual setpoint and the external
setpoint signal in control mode controlled
Example: At a sensor value of 0 psi, a setpoint set of 50 psi
min
and an external setpoint of 80 % (an 8 V analog signal to Terminal
4 if using an analog signal of 0-10 V), the actual setpoint will be
as follows:
Actual
= (setpoint - sensor
min
setpoint
= (50 - 0) x 80 % + 0
= 40 psi
In control mode uncontrolled, the setpoint can be set externally
within the range from the min. curve to the setpoint set on the
pump or by means of the R100. Typically the setpoint is set to
100 % when the control mode is uncontrolled (see section
4.6 Typical display settings for analog-input E-pumps).
Actual setpoint
Max
Setpoint set by means of
control panel, R100 or PC Tool
E-products
Actual
setpoint
Min
0 10 V
0 20 mA
4 20 mA
Fig. 26 Relation between the actual setpoint and the external
setpoint signal in control mode uncontrolled
max
min
External setpoint signal
) x % + sensor
external setpoint min
curve
curve
External setpoint signal
23