Endress+Hauser Proline Prowirl 73 - Page 129

Proline Prowirl 73 Description of device functions
Endress+Hauser 129
OUTPUT SIGNAL Prerequisite
The function is only available if PULSE was selected in the OPERATION MODE function
(ä 122).
Description
For selecting the output configurations of the pulse output.
Options
PASSIVE – POSITIVE
PASSIVE – NEGATIVE
Factory setting
PASSIVE – POSITIVE
Explanation
PASSIVE = power is supplied to the pulse output by means of an external power supply.
Configuring the output signal level (POSITIVE or NEGATIVE) determines the quiescent
behavior (at zero flow) of the pulse output. The internal transistor is activated as follows:
• If POSITIVE is selected, the internal transistor is activated with a positive signal level
• If NEGATIVE is selected, the internal transistor is activated with a negative signal level
(0 V)
!
Note!
In the case of passive output configuration, the output signal levels of the pulse output
depend on the external wiring (see examples).
Example for a passive output circuit (PASSIVE)
If PASSIVE is selected, the pulse output is configured as an open collector.
A0001225
m
Open collector
n
External power supply
!
Note!
For continuous currents up to 25 mA (I
max
= 250 mA ÷ 20 ms).
Example for output configuration PASSIVE-POSITIVE
Output configuration with an external pull-up resistor. In the quiescent state (at zero
flow), the output signal level at the terminals is 0 V.
A0004687
m
Open collector
n
Pull-up resistor
o
Transistor activation in "POSITIVE" quiescent state (at zero flow)
p
Output signal level in quiescent state (at zero flow)
In the operating state (flow present), the output signal level changes from 0 V to a
positive voltage level.
A0001975
(Continued on next page)
Function description, PULSE, FREQUENCY, STATUS group
1
5
8 3
7
+
-
=
U =30VDC
max
m
n
U =30VDC
max
+
U (V)
t
U (V)
t
o
p
m
n
U (V)
t