Endress+Hauser PROMAG 33 - Page 56

Function group
PULSE / FREQ. OUTPUT
OUTPUT SIGNAL
With this function the pulse/frequency output can be configured as required,
for example for an external counter.
ACTIVE → Internal power supply used (+24 V)
PASSIVE → External power supply required
6
PASSIVE / POSITIVE
PASSIVE / NEGATIVE
ACTIVE / POSITIVE
ACTIVE / NEGATIVE
7
PASSIVE = OPEN-COLL or ACTIVE = PUSH-PULL
(see Figures above for details)
1
5
8 3
7
+
-
=
Recommended for:
– high output frequencies
– continuous currents up to 25 mA (I
max
= 250 mA for 20
Internal power
supply
24 V DC
ACTIVE
Push-
Pull
20 (HART)
26 (RS 485)
21 (HART)
27 (RS 485)
Mech. counter
(example)
short circuit-
resistant output
ba009y64
B
B
U [V]
U [V]
t
t
24
24
0
0
ACTIVE / POSITIVE
pulses
ACTIVE / NEGATIVE
pulses
ba009y65
1
5
8 3
7
+
-
=
Recommended for:
– low output frequencies
– continuous currents up to 25 mA (I
max
= 250 mA for 20 ms)
Open Collector
PASSIVE
20 (HART)
26 (RS 485)
21 (HART)
27 (RS 485)
SPS, electronical
counter (example)
External
power supply
U
max
= 30 V DC
ba009y66
B
B
t
t
a
a
b
b
Transistor
PASSIVE / NEGATIVE
pulses
PASSIVE / POSITIVE
pulses
ba009y67
a = conductive
b = non-conductive
B = pulse width
6 Description of Functions Promag 33
56 Endress+Hauser