Endress+Hauser Proline Prosonic Flow 93C Description Of Device Functions page 61

Device functions Proline Prosonic Flow 93C PROFIBUS DP/PA
Endress+Hauser
OUTPUTS → PULSE/FREQUENCY OUTPUT 1 → CONFIGURATION (PULSE)
OUTPUT SIGNAL
!
(4226)
Function is not available unless the PULSE setting was selected in the
OPERATION MODE function (4200).
For selecting the output configuration of the pulse output.
Options:
PASSIVE - POSITIVE
PASSIVE - NEGATIVE
ACTIVE - POSITIVE
ACTIVE - NEGATIVE
Factory setting: PASSIVE - POSITIVE
Explanation
• PASSIVE = power is supplied to the pulse output by means of an external power
• ACTIVE = power is supplied to the pulse output by means of the device-internal
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
!
With the passive output configuration, the output signal levels of the pulse output depend
on the external circuit (see examples).
Example for passive output circuit (PASSIVE)
If PASSIVE is selected, the pulse output is configured as an open collector.
m
n = External power supply
!
For continuous currents up to 25 mA (I
Example for output configuration PASSIVE-POSITIVE:
Output configuration with an external pull-up resistance.
In the quiescent state (at zero flow), the output signal level at the terminals is 0 V.
m
n = Pull-Up-Resistance
o
p
In the operating status (flow present), the output signal level changes from 0 V to a
positive voltage level.
(continued on next page)
Functional description
(only with PROFIBUS DP)
Note!
supply.
power supply.
level (0 V).
Note!
m
= Open Collector
Note!
U (V)
m
o
t
= Open Collector
= Transistor activation in "POSITIVE" quiescent state (at zero flow)
= Output signal level in quiescent state (at zero flow)
U (V)
6 Block OUTPUTS
1 5 7 8 3
+
n
=
U = 30 V DC
max
-
= 250 mA / 20 ms).
max
+ U = 30 V DC
max
n
U (V)
p
t
A0001225
t
A0004687
A0001975
61