<5. Functions>
82
IM 01E21A02-03EN
5.5 Auxiliary Calculation Function
5.5.1 Fluid Flow Direction Setting
The arrow indicated on the surface of the sensor indicates a fluid flow direction. At shipment from
the manufacturing factory, a flow rate is measured assuming that the arrow direction is forward.
By changing the parameter settings, this product can measure the flow rate, assuming that the
reverse direction is forward against the arrow direction.
The setting can be configured with the following parameter.
Menu path
Display
Device setup ► Detailed setup ► AUX calculation ► (see below)
F
OUNDATION
Fieldbus
Device Configuration ► STB ► Device Configuration ► Configuration ► AUX Calculation
► (see below)
Block
Name
Relative
Index
Parameter
Description
Display
F
OUNDATION
Fieldbus
STB
88
Flow direct
Flow Direction
Specifies the fluid flow
direction.
From the table below, select the fluid flow direction.
Selection
Description
Display
F
OUNDATION
Fieldbus
Forward
Forward
The arrow direction of the sensor is forward.
Reverse
Reverse
The reverse direction of the arrow of the sensor is forward.
5.5.2 Rate Limit Function Setting
If the rate limit function is used, it becomes possible to reduce noises that cannot be all cleared
only by lengthening the damping time constant. When a step signal or a sudden signal due to a
slurry fluid is input, this function judges whether the signal is a flow rate signal or a noise signal.
This judgment is made based on the high/low limit value (rate limit value) and the rate limit
function continuation time (dead time), causing the noise signal over the rate limit value to be cut
off.
The rate limit value should be specified with the percentage (%) for the span of the process value
PV-mapped in Subsection 5.1.2. If the rate limit function is not used, set “0” to the dead time.
The setting can be configured with the following parameters.
Menu path
Display
Device setup ► Detailed setup ► AUX calculation ► (see below)
F
OUNDATION
Fieldbus
Device Configuration ► STB ► Device Configuration ► Configuration ► AUX Calculation
► (see below)
Block
Name
Relative
Index
Parameter
Description
Display
F
OUNDATION
Fieldbus
STB
89
Rate limit
Rate Limit
Specifies the rate limit value.
STB
90
Dead time
Dead Time
Specifies the dead time.
STB
91
Noise filter
Noise Filter
Specifies the noise filter (rate
limit value and dead time).
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