5/2004 Manual for connection and operation of the EV-94 EB page 7 of 28
3.3.6. Connecting a frequency- or rotation-signal
When measuring frequency or rotation three different input signals can be selected in the device’s con-
figuration.
There is the possibility of connecting an active signal (= TTL, ...), a passive sensor-signal with NPN
(= NPN-output, push-button, relay, ...) or PNP (= a PNP output switching to +Ub, high-side push-button, ...).
When configuring the device with a NPN switching output, a pull-up-resistor (~11k_ referring to +3.3V) is
connected internally. So when You use a device with NPN output You don‘t need to connect a resistor
externally.
When configuring the device with a PNP switching output, a pull-down resistor (~11k_ referring to GND)
is connected internally. So when You use a device with PNP output You don‘t need a resistor externally.
It may be that your measuring-signal source needs the connection of an external resistor e.g. the pull-up-
voltage of 3.3V is not enough for the signal source, or you want to measure in the top level frequency
range. In this case the input signal has to be treated like an active signal and you have to configure the de-
vice as „TTL“.
Hint:
when connecting the device You have to take care not to exceed the limits of the input
voltage respective the input current of the frequency-input.
Connection of a transducer (with separate power supply)
Connection of a transducer (without separate power supply)
with TTL or PNP output and external resistor for current limitation.
with TTL or PNP output and external resistor for current limitation.
C
onnection of a transducer (with separate power supply) with NPN output.
Connection of a transducer (without separate power supply) with NPN output.
Connection of a transducer (with separate power supply) with NPN output
Connection of a transducer (without separate power supply) with NPN output
and needed external resistor
and needed external resistor.
Hint: Rv = 3k_ (with power supply voltage = 12V) or 7k_ (with power supply voltage = 24V), device configuration: Sens = TTL
+
_
Supply
9-28 VDC
+
_
Supply
for Transducer
4
5
7
9
Transducer
+Uv
Sig.
-Uv
+
_
Supply
9-28 VDC
4
5
9
Transducer
+Uv
Sig.
-Uv
+
_
Supply
9-28 VDC
4
5
7
9
+
_
Supply
for Transducer
Rv
Transducer
+Uv
Sig.
-Uv
+
_
Supply
9-28 VDC
4
5
9
Rv
Transducer
+Uv
Sig.
-Uv
Transducer
+Uv
Sig.
-Uv
+
_
Supply
9-28 VDC
+
_
Supply
for Transducer
4
5
7
9
+
_
Supply
9-28 VDC
4
5
9
Transducer
+Uv
Sig.
-Uv
