User Manual

Page 53
EA Elektro-Automatik GmbH
Helmholtzstr. 31-33 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
[e-mail]
PSI 9000 3U Series
3.4.4.5 Simplied diagram of the pins
+
Digital Input (DI)
The internal circuit requires that a switch
with low resistance should be used (relay,
switch, circuit breaker etc.) in order to
send a clean signal to the DGND.
A digital output from a circuit or PLC may
notbesufcientifnotan“opencollector”.
V~0.5
AGND
Analog Input (AI)
High resistance input (impedance
>40k....100kΩ)foranOAcircuit.
4.7k
12V
+10V
Digital Output (DO)
A quasi open collector, realised as high
resistance pull-up against the internal sup-
ply. In condition LOW it can carry no load,
merely switch, as shown in the diagram
with a relay as example.
V~2
AGND
Analog Output (AO)
Output from an OA circuit, only mini-
mallyimpedant.Seespecications
table above.
3.4.4.6 Application examples
a) Switching off output with pin “Rem-SB”
The pin Rem-SB can be used in remote control to switch the output on and off. It is recom-
mended that a low resistance contact such as a switch, relay or transistor is used to switch
the pin to ground (DGND).
A digital output, e.g. from a PLC, may be unable to cleanly effect this as
it may not be of low enough resistance. Check the specication of the
controlling application. See also 3.4.4.5 above.
b) Remote control of current and power
Requires remote control to be activated (Pin “Remote” = LOW)
The set values PSEL CSEL are generated from, for example, the
reference voltage VREF using potentiometers for each. Hence the
power supply can selectively work in current limiting or power limit-
ingmode.Accordingtothespecicationofmax.5mAfortheVREF
output,potentiometersofatleast10kΩmustbeused.
The voltage set value VSEL is permanently assigned to VREF and
will thus be permanently 100%.
If the control voltage is fed in from an external source it is necessary to
consider the input voltage ranges for set values (0...5 V oder 0...10 V).
Use of the input voltage range 0...5 V for 0...100%
set value halves the effective resolution.
Example with external
voltage source
Example with
potentiometers
c) Reading actual values
Via the AI the output values for current and voltage can be monitored. These can be
read using a standard multimeter or similar.