WIKA DI15 - Manual (Page 9)

Operating Instructions Digital Indicator DI15
V1.3 • 02/2011 - 9 -
3.4. Connecting switching outputs
The device features two switching outputs, with three different operating modes for each switching out-
put, which are:
Low-Side: “GND-switching“ NPN output (open-collector)
The switching output is connected to the negative rail of the supply voltage (connection 3
or 5) when active (switching output on).
High-Side: “+Ub-switching“ PNP output (open-collector)
The switching output is connected to the positive rail of the supply voltage (connection 4)
when active (switching output on).
Push-Pull: The switching output is connected to the negative rail of the supply voltage (connection 3
or 5) when inactive. When the switching output is active, it’s connected to the positive rail
of the supply voltage (connection 4).
In case of configuring one output as an alarm output, the output will be active in idle state (no alarm pre-
sent). The output transistor switches or the push-pull output changes from +Uv to –Uv when an alarm
condition occurred.
Hint: In order to avoid unwanted or wrong switching processes, we suggest to connect the
device’s switching outputs after you have configured the device’s switching outputs
properly.
Please take care that you must not exceed the limits of the voltage and of the maximum current
of the switching outputs (not even for a short period of time). Please take extreme care when
switching inductive loads (like coils or relays, etc.) because of their high voltage peaks, protec-
tive measures to limit these peaks have to be taken.
When switching large capacitive loads a series resistor for current limitation needed, because of
the high turn-on-current of high capacitive loads. The same applies to incandescent lamps,
whose turn-on-current is also quite high due to their low cold resistance.
3.4.1. Connection with configured low-side-switching output (NPN output, switching to GND)
Connection of consumer loads (relay and lamp) Connection of consumer loads (relay and lamp)
(without individual supply voltage) (with individual supply voltage)
3.4.2. Connection with configured high-side-switching output (PNP output, switching to +Uv)
Connection of consumer loads (relay and lamp)
+
_
Supply
9-28 VDC
+
_
Supply
for load
1
2
3
4
5
+
-
Relay
Hints:
Connections 3 and 5 are internally electrically connected.
When switching higher currents (> 50 mA) , the –Uv connec-
tion should not be attatched to the device (connection 3) but to
the –Uv connection of the external power supply unit.
When doing this, you get rid off ground displacement.
+
_
Supply
9-28 VDC
1
2
3
4
5
+
-
Relay
+
_
Supply
9-28 VDC
1
2
3
4
5
+
-
Relay