Presys DMY-2030-F Technical Manual page 21

PRESYS
⏐ Instruments
ANNUL disables the reading of the corresponding input. In operation level, the
NONE mnemonic is indicated for a disabled input. In order to enable the input to return
to its normal operation, just confirm one of the parameters Lim Low, Lim High, Eng Low
or Eng High in SCALE option from INPUT level. From the operation level, go to the
INPUT configuration level, enter the SCALE option and select one of the parameters
above; the value of the parameter will start blinking, then confirm it by pressing ENTER.
The examples below illustrate the configuration of Lim Low, Lim High, Eng Low,
Eng High and DC.PT parameters according to the specifications found in some of the
most common applications of the frequency Indicator.
Example 1: Frequency indication in Hz. For a 0 to 400Hz operation range and 0.0
to 400.0Hz indication, configure the input as: Lim Low = 0, Lim High = 400 (Hz),
DC.PT = 888.8, Eng Low = 0.0 and Eng High = 400.0 (Hz).
Example 2: Frequency indication in Hz. For a 0 to 300Hz operation range and
0.00 to 300.00Hz indication, configure the input as: Lim Low = 0, Lim High = 300,
DC.PT = 888.88, Eng Low = 0.00 and Eng High = 300.00 (Hz).
Example 3: Frequency indication in rpm. The conversion of the frequency f
between Hz and rpm is accomplished by:
For a 0 to 400 Hz operation range and 0 to 24000 rpm (= 60 × 400) indication,
configure the input as: Lim Low = 0, Lim High = 400 (Hz), DC.PT = 88888 (no decimal
point), Eng Low = 0 and Eng High = 24000 (rpm).
Example 4: Measurement of the revolution frequency of a toothed wheel with a
magnetic pickup sensor. The relationship among the sensor output frequency f, the
toothed wheel revolution frequency f
f in Hz
f in rpm
For a 0 to 1650 Hz operation range from the magnetic pickup, a toothed wheel
with N = 11 and 0 to 9000 rpm (= 60 x 1650 / 11) indication, configure the input as:
Lim Low = 0, Lim High = 01650 (Hz), DC.PT = 88888 (no decimal point), Eng Low = 0
and Eng High = 09000 (rpm).
Example 5: Measurement of revolution frequency with an encoder (one channel).
The relationship among the encoder output frequency f, its shaft revolution frequency f
and the number of pulses per revolution N is given by:
Operation
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f (rpm) = 60 × f (Hz)
or
f (Hz) = f (rpm) / 60.
and the number of teeth N is given by:
R
f in Hz
R
f = f / N
R
= f / (60 × N)
f
R
DMY-2030-F / DMY-2030-F Light
f in rpm
R
= 60 × f / N
f
R
f = f / N
R
R