Omega DPF20 Series User Manual

8
DPF20 Frequency, rate, total or period counter Instruction Manual
Special working mode for applicaons with low frequency signals.
Applies to ratemeter (‘rt.6’), ratemeter quadrature (‘rtq.7’) and peri-
odmeter (‘Prd.8’). The ‘SLOW’ mode allows to measure slow fre-
quencies down to 1 mHz (0,001 Hz) and is funconal up to 200 Hz.
The ‘SLOW’ mode provides the fastest response me possible for a
given applicaon, calculang the frequency and the period based on
the me between consecuve impulses.
The ‘SLOW’ mode needs to dene the parameter ‘maximum waing
me’ to a value between 1 and 1000 seconds. If this me expires
without a single impulse being received, the reading jumps to ‘0’
(both for ratemeter and periodmeter modes). The ‘GATE’ parameter
is not used if ‘SLOW’ mode is acve.
In ‘ratemeter quadrature’ (‘rtq.7’) mode, the acvaon of the
‘SLOW’ mode calculates the frequency based on the me between
consecuve impulses received on channel A, and calculates the
sense of turn (clockwise or counter-clockwise) by comparing each
impulse with the state of channel B. The ‘edge’ parameter is xed to
a ‘1--1’. Typical applicaon for quadrature frequency measure with
two inducve sensors at low frequency.
1.13 Funcon ‘Trigger Sense’
Special working mode for counter applicaons with high frequency
signals, up to 250 KHz. Applies only to the counter mode (‘cn.1’).
The acvaon of the ‘FAST’ mode congures the signal detecon by
rising edge. The rst edge detected, either rising or falling edge, aer
the instrument restart (power-up, or conguraon change) is used
for internal inializaon and will not be counted as impulse.
1.14 Funcon ‘cycle counter’ 1.15 ‘SLOW’ mode
The trigger level is automacally congured when selecng a sensor
from the ‘Sensor / Conguraon’ (‘SnSr’ / ‘Auto’) menu list. The trig-
ger level can be also manually modied from the ‘SnSr’ / ‘TrIG’ menu
entry. The selected value applies to channels ‘A’ and ‘B’ (the reset has
a xed trigger level at 2.5 Vdc).
At the ‘SnSr’ / ‘TrIG’ menu, the instrument shows the trigger level
and two vercal leds to the le. These leds inform in real me about
the status (‘0’ or ‘1’) of the input channels ‘A’ and ‘B’. When the led
switches between up and down posion, it indicates that impulses
are being detected at the input. If the instrument does not detect
impulses, the led posions remain xed.
Increase the trigger level pressing key ‘UP’ (5) and decrease press-
ing key ‘LE’ (3).
Vdc
Time
Trigger level
‘1’
‘0’
Signal detected
channel ‘A’
Status ‘1’
Trigger level
Status ‘0’
Leds of the ‘Trigger
Sense’ funcon
channel ‘B’
1.16 ‘FAST’ mode
Reading
Time
Setpoint 1
Impulse counter, with ‘reset to preset’
when setpoint 1 is reached
Preset
Time
Cycle counter
0
1
2
3
The counter modes allow to acvate a reset funcon (to ‘0’ or to
‘preset’ value) when an alarm setpoint is reached. With this congu-
raon, the instrument counts in cycles, counng from the instrument
preset value up to the alarm setpoint. Each cycle is counted and ac-
cumulated into an internal memory, accessible through the ‘fast ac-
cess’ menu (key UP (5) (see secon 1.19.12)).
To reset the memory of cycles, visualize the value at the ‘uP’ menu,
then press the (5) key and the ‘rSt’ message appears. Press (<) to
reset.

Omega DPF20 Series Specifications

General

Brand	Omega
Model	DPF20 Series
Category	Measuring Instruments
Language	English