Operators Manual
ALS 321/421
Release 2/08
Page 23
Connections
4.2
Input signals
This machine (dispenser) is provided with photo coupled inputs for:
the product sensor signal
an inhibit signal for inhibiting labelling
a signal from an OD control which shows the end of the material roll.
The inputs are galvanically separated through photo couplers to connect to PNP or NPN out-
puts. The wiring and the connection of the signal plug is shown otherwise. The input voltage
across the inputs must be in the range of 15 V to 30 V to switch active.
ln+
Signal
ln-
Machine
Bridge
Bridge
(alternative switch)
+24V DC
NPN
Opto-
isolator
2K2
ln+
Signal
ln-
Machine
(alternative switch)
+24V DC
PNP
Opto-
isolator
2K2
Figure 13 Input connection and input circuit
