KROHNE VFM 5090 EN - Manual (Page 31)

Fct. 1.3.6 0/4 mA POWER
Enter the power value at which you want current
output at its minimum 0 mA or 4 mA.
LIMITS : No limits
APPEARS : If meter type is HEAT METER or NET
HEAT METER and Fct. 1.3.5. VARIABLE I is
POWER or NET POWER.
Fct. 1.3.7 20 mA POWER
Enter the power value at which you want current
output at its minimum 20 mA.
LIMITS : No limits
APPEARS : If meter type is HEAT METER or NET
HEAT METER and Fct. 1.3.5. VARIABLE I is
POWER or NET POWER
Fct. 1.4.0 FREQ. OUTP. F
This submenu groups frequency output related
functions.
APPEARS – Always (Not when output type is RS
485 or RS 232)
Fct. 1.4.1 FUNCTION F frequency output
Choose YES - to make frequency output active as per
functions Fct. 1.4.2 to Fct. 1.4.4 NO makes frequency
output inactive (0 Hz)
LIMITS - Not applicable.
APPEARS - Always. (Not when output type is RS
485 or RS 232)
Fct. 1.4.2 RANGE F frequency output range value
The frequency output range value is the frequency
that corresponds to max. flow (Fct. 1.1.2). The other
point is always 0 Hz for 0 flow because frequency
output is designed for use with external totalizers. It is
also possible to define range f in terms of pulses/unit
flow.
Example -
Assume max. flow (Fct. 1.1.2) = 1000 Kg/hr then
range f = 10000 pulses/hr (at max. flow) and
range f = 10 pulses/Kg are identical. The latter
method is better because it is easy to infer that
totalizer will have a least count of 0.1 Kg (10 pulses
per Kg = 1pulse per 0.1 Kg) and totalizer
programming will be independent of max. flow. The
various options of units for RANGE F are given
below.
For volumetric flow -
l PULSE/hr l PULSE/min l PULSE/sec
l PULSE/m3 l PULS/Litre l PULS/ft3
l PULS/cft l PULS/cuft l PULS/US.Gal
l PULS/UK. Gal
For normalized volumetric flow -
l PULSE/hr l PULSE/min l PULSE/sec
l PUL
/NormM3
l PULS/
NormL
l PULS/Sft3
l PULS/Scft
Or mass flow -
l PULSE/hr l PULSE/min l PULSE/sec
l PULS/Kg l PULS/t l PULS/Lb
LIMITS - 0.0028 Hz TO 10,000 Hz. These limits are
also applied when programming in pulses per unit
flow units. All the necessary conversions for the same
are done internally.
APPEARS - If Fct. 1.4.1 FUNCTION F is YES.
Fct. 1.4.3 PULS.WIDTH pulse width
You can limit the duration of maximum active pulse
width of the frequency output for frequencies less
than or equal to 10 Hz. All options that may appear
are listed below. Only the possible options that are
available (depending on programming of Fct. 1.4.2
RANGE F) to choose are displayed during actual
programming.
l 500 mSec l 200 mSec l 100 mSec.
l 50 mSec l 30 mSec l 50 %
This function helps to minimize the overheating of
electro-mechanical counter coils.
LIMITS - Not applicable.
APPEARS - if Fct. 1.4.1 FUNCTION F is YES.
Fct. 1.4.4 VARIABLE F frequency output selection
function
Selects any one of the three options available for
frequency output.
Options are listed below :
· FLOW
· POWER
· NET POWER
LIMITS : Not applicable
APPEARS – If meter type is HEAT METER or NET
HEAT METER. For meter type HEAT METER ,
only flow and power options are available. For meter
type NET HEAT METER, all three options are
available.
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