Siemens SITRANS F M Intermag 2, Operating Instructions Manual

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Operation
5-28
SITRANS FM Intermag 2 Flow Transmitter
Operating Manual - A5E00102775-03
- Measuring direction , menu item 3.1.5.2
The measuring system is able to detect the flow in forward and
backward direction and to pass on the appropriate signal
proportionally to the analog or digital output. In ”forwards”
parameterization, only signals in this direction are output or
accumulated internally.
Example 1: Hysteresis = 0 %
reverse
Flow in %
of range
0
b
a
forwards
Example 2: Hysteresis = 1 %
reverse
Flow in %
of range
0
b
a
forwards
-1 +1
Switching status’ of the relay for selected signal type:
- Contact closes: a ! Relay contact closed
b
!
Relay contact open
- Contact opens: a ! Relay contact open
b ! Relay contact closed
Figure 5-12 Hysteresis flow direction
- Hysteresis , menu item 3.1.5.3
The limit values (menu items 3.1.5.1 and 3.1.5.2 ) can have a
hysteresis added to prevent ”fluttering” of the switching output
(see Figure 5-12).
This setting is made in % of the set full scale value in the menu
item
3.1.5.3 ”Hysteresis”. If, for example, the hysteresis is 1 %,
the relay contact does not switch until a flow of •1% of the full
scale value and returns to the original position at a flow of +1%
of the full scale value.