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Flow-X─ Function Reference
4-269
Flow-X General functions - fxROCAlarm
fxROCAlarm
Description
The function checks if a value does not change its value at a rate that is higher than a specific limit
(‘rate of change’).
Function inputs and outputs
Function inputs Remark EU SW tag Range Default
Name Optional tag name,
tag description and
tag group
Input value Must be linked to
another cell Same as linked
cell -1e11..1e11 0
Rate of change
limit The unit depends
on the 'Deviation
type' Absolute: Same as
input value 1 / s
Relative : % /s ROCLIM 0..1e11 0
Enabled Enables or disabled
the alarm True or false True
Alarm type 1: Alarm
2: Warning 1
Function outputs Remark EU SW tag Alarm Fallback
Rate of change alarm 0: Normal
1: Alarm - ROCALM ROCALM
Logic
A 'Rate of change alarm' is raised when the absolute difference between two consecutive values divided
by the calculation cycle time in seconds is more than the limit.
fxSarasota_C
The function calculates the density from a frequency input signal provided by a Sarasota densitometer
and corrects it for temperature and pressure effects in US customary units.
Note: The calibration constants also need to be in US customary units (°F, psi and lbm/ft3).
Function inputs Remark EU SW tag Range Default
Name Optional tag name, tag
description and tag
group
Periodic time In microseconds
Equals 1000 divided by
the frequency in [Hz]

s
0..1e6 0
Line temperature Used when temperature
correction is enabled °F -
273.15..+500 20
Line pressure Used when pressure
correction is enabled psig 0..200 0
Temperature
correction 0: Disabled
1: Enabled - TEMPCOR 1
Pressure correction 0: Disabled
1: Enabled - PRESCOR 1
Reference
temperature Used when temperature
correction is enabled °F REFTEMP 0..100 20
Reference pressure Used when pressure psig REFPRES 0..100 0