HF197AEN_v0501_04
Page 16
4 - POWER MANAGEMENT
When used with the internal battery (type PB / PC), the user can expect reliable measurement over
a long period of time. The F197-A has several smart power management functions to extend the
battery life time significantly. Two of these functions can be set:
LCD NEW
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The calculation of the display-information influences the power
consumption significantly. When the application does not require a fast
display update, it is
strongly advised
to select a slow refresh rate.
Please understand that NO information will be lost; the input signal will be
processed and the output signals will be generated in the normal way.
The following can be selected:
Fast - 1 sec - 3 sec - 15 sec - 30 sec - off.
Example 3:
Battery life-time
battery life-time with a FAST update: about 3 years.
battery life-time with a 1 sec update: about 7 years.
Note:
after a button has been pressed by the operator - the display
refresh rate will always switch to FAST for 30 seconds. When "OFF" is
selected, the display will be switched off after 30 seconds and will be
switched on as soon as a button has been pressed.
BATTERY-MODE
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The unit has two modes: operational or shelf.
After "shelf" has been selected, the unit can be stored for several years; it
will not count pulses, the display is switched off but all settings are stored.
In this mode, power consumption is extremely low.
To wake up the unit again, press the SELECT-key twice.
5 - SENSOR
f setup 11 has been enabled, following functions are used to scale the senor signaI.
SIGNAL
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The F197-A can process the 4-20mA signal in two ways:
Interpolation: the signal is processed linear
V = S x I
Square root: for differential pressure
V = S
√
I
where:
V = Value: the calculated value
S = Span: the maximum value at 20mA. The span is programmed
with setting 15.
I = Input: the scaled analog value; in these formulas value 0 (zero)
for (0)4mA and value 1 (one) for 20mA.
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