User’s Manual BDF-xx-TF
FEMA ELECTRÓNICA - Page 8
Programming example
The default programming for the BDF Ratemeter units is 1 impulse/second = 1. If changing this relation is needed, then the
programming codes need to be accessed to change the scale factors of the unit. We take as an example the reprogram-
ming to 52 impulses/second = 247 meters/minute.
a.- The scale factors available and the values we can activate are the following :
«Scale Factor»
selectable between -5.9999 and +5.9999
«Multiplication Factor» selectable at x1000, x100,x 10, x1, x0.1, x0.001
«Time Multiplication»
selectable at x1, x60, x3600
b.- To generate a total scale factor of 4,75 (= 247 / 52) we can assign the following values
«Scale Factor»
= 4,7500
«Multiplication Factor » = x1
«Time Multiplication» = x1
c.- The codes to program are
«3»
4,7500
«64 4#»
x1
«62 1#»
x1
Still, we need to program the Time Base which defines a «time window» where the unit will detect impulses, and will divide
the received impulses by the Time Base value, thus getting the frequency in impulses per second. The Time Base also de-
fines the refresh on display. By default, the Time Base of 0,5 to 1 second will be enough. In case the signal is too slow (0,1
impulses per second, for example) we would need a bigger Time Base. For 0,1 impulses per second we have 1 impulse
every 10 seconds. If we define a Time Base of 1 second, the Ratemeter will always read «0000» because no impulse is
detected, and every once a while, 1 impulse will be detected.
d.- To program the same relation (52 impulses per second = 247.0 meters/minute), but with 1 decimal point, we need to
program the following:
«Scale Factor»
= 4,7500
«Multiplication Factor» = x10
«Time Multiplication» = x1
«Decimal Point»
= XXX.X
e.- The codes to program are
«3»
4,7500
«64 3#»
x1
«62 1#»
x1
«65 2#»
Decimal Point on at XXX.X
The possible combinations of scale factors and decimal points are very big. Take into consideration that the decimal point
is only a led lightning, but it will not move the readings neither to the left nor to the right, and it will not multiply the reading
in any case. Start always defining parameter «3» which is the only one able to define precise values, and then look for the
appropriate fixed multiplication factors.
