Siemens SITRANS F US Operating Instructions Manual page 36

Measurement direction, menu 3.1.5.2
SITRANS FUS060 is able to measure in both flow directions (forward and reverse) or in forward
direction only. The selection is made by the setting.
– forward + reverse
– forward only
If "forward" is parameterized, signals are only output or accumulated internally for a flow in this
direction.
Setting "Forward+reverse" Setting "Forward"
Hysteresis of flow, menu 3.1.5.3
Signalling of flow direction can operate with a hysteresis determined by the user. The setting
is made in % of full scale value in menu item "3.1.5.3 Hysteresis". If, for example, the hysteresis
is 1%, the relay contact does not switch until flow is –1% of full scale value and it returns to its
original position when flow is +1% of full scale value.
The operating principle of the relay (digital output 2), contact open or closed in forward flow-
direction is determined in menu item "4.3.2 Signal Type".
Example 1: Hysteresis = 0% Example 2: Hysteresis = 1%
The other hysteresis menus are of the same principle.
Note
The low flow cut off suppression has no influence on signalling of flow direction.
36 SFIDK.PS.029.E5.02 / SW 2.01.07