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EA Elektro-Automatik GmbH
Helmholtzstr. 31-37 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
EL 9000 B 15U/24U Series
3.5.4.6
Simplified diagram of the pins
++
Digital Input (DI)
The DI is internally pulled up and thus it re
-
quires to use a contact with low resistance
(relay, switch, contactor etc.) in order to
clearly pull the signal down to DGND.
V~0.5
AGND
Analog Input (AI)
High resistance input (impedance
>40 k
Ω
....100 kΩ) for an operational
amplifier circuit.
4K
7
12V
+10V
Digital Output (DO)
A quasi open collector, realised as high
resistance pull-up against the internal
supply. The design doesn’t allow the pin
to be loaded, but to switch signals by
sinking current.
V~2
AGND
Analog Output (AO)
Output from an operational amplifier
circuit, with low impedance. See
specifications table above.
3.5.4.7
Application examples
a) Switching the DC input with pin REM-SB
A digital output, e.g. from a PLC, may be unable to cleanly pull down the pin as
it may not be of low enough resistance. Check the specification of the controlling
application. Also see pin diagrams above.
In remote control, pin REM-SB is used to switch the DC input of the device on and off. This function
is also available without remote control being active and can on the one hand block the DC input
from being switched on in manual or digital remote control and on the other hand the pin can switch
the DC input on or off, but not standalone. See below at “Remote control has not been activated”.
It’s recommended that a low resistance contact such as a switch, relay or transistor is used to switch
the pin to ground (DGND).
Following situations can occur:
• Remote control has been activated
During remote control via analog interface, only pin REM-SB determines the states of the DC input, according to
the level definitions in
. The logical function and the default levels can be inverted by a parameter in the
setup menu of the device. See
If the pin is unconnected or the connected contact is open, the pin will be HIGH. With parameter
“Analog interface Rem-SB” being set to “Normal”, it requests “DC input on”. It means, when
activating remote control, the DC input will instantly switch on.
• Remote control has not been activated
In this mode of operation pin REM-SB can serve as lock, preventing the DC input from being switched on by any
means. There are following possible situations:
DC
input
+
Level on
pin
REM-SB
+
Parameter
„Analog
interface
Rem-SB“
Behavior
is off
+
HIGH
+
Normal
The DC input isn’t locked. It can be switched on by pushbutton “On/
Off” (front panel) or via command from digital interface.
LOW
+
Inverted
+
HIGH
+
Inverted
The DC input is locked. It can’t be switched on by pushbutton “On/
Off” (front panel) or via command from digital interface. When trying
to switch on, a pop-up in the display resp. an error message will
be generated.
LOW
+
Normal
