Response Of The Relay Output - Endress+Hauser Proline Prosonic Flow 93C Description Of Device Functions

6 Block OUTPUTS
80
6.3.4

Response of the relay output

General
If you have configured the relay output signal for "LIMIT VALUE" or "FLOW DIRECTION", you
can define the requisite switch points in the ON-VALUE and OFF-VALUE functions. When the
measured variable in question reaches one of these predefined values, the relay output switches as
shown in the illustrations below.
Relay output configured for limit value
The relay or status output switches as soon as the measured variable undershoots or overshoots a
defined switch point.
Application: Monitoring flow or process-related boundary conditions.
Measured variable
A = Maximum safety → m
OFF-VALUE >
B = Minimum safety → m
OFF-VALUE <
C = Minimum safety → m
OFF-VALUE =
o
= Relay de-energized
Relay output configured for "flow direction"
The value you entered in the ON-VALUE function defines the switching point for the positive and
negative directions of flow.
If, for example, the switch point you define is = 1 m
3
up at +1 m /h. Set the switch point to 0 if your process calls for direct switchover (no switching
hysteresis). If low flow cut off is used, it is advisable to set hysteresis to a value greater than or equal
to the low flow cut off rate.
-Q
a = Relay energized
b = Relay de-energized
Device functions Proline Prosonic Flow 93C PROFIBUS DP/PA
A B
m n
m
o o
n
ON-VALUE
n
ON-VALUE
n
ON-VALUE (this configuration should be avoided)
3
/h, the relay drops out at –1 m
Off-value / on-value
-1 0 +1
b
C
n
m n
o
3
/h and pulls
Q
a
Endress+Hauser
t
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