Trumeter 7760 Manual De Instrucciones página 2

DESCRIPTION
This programmable unit monitors both rate and totalising count simultaneously. While the
display is indicating units per minute in Period mode a "background" totaliser keeps count
of incoming pulses. The Reset button on the front panel toggles the display between
"Periodmode rate" and "count" readings and is also used to reset the count (hold key in
for 3 seconds). All programming is carried out using the two pushbuttons on the front
panel.
The ratemeter function can operate in either Period or Gated mode. The display indicates
the mode and whether the multiplying or dividing prescaler is in use. (The totaliser
function is not available in Gated mode.)
FUNCTIONS and MODES
GATED MODE utilises a variable time base and counts the number of pulses occurring
within the time frame (number of pulses through the "gate").
PERIOD MODE derives its output by computing the reciprocal of the time period
measurement between successive pulses.
TOTALISER function. The unit operates as a totalising up counter when the
Tacho/Ratemeter is in Period Mode.
Mode selection, prescaling and decimal point positioning are all carried out in
programming mode (see page 4).
MODE APPLICATIONS
Period mode is suitable for relatively slow events such as items passing on a conveyor
belt. An application which uses the dividing prescaler is measurement of shaft rotation by
counting the passing teeth on a gear. If the gear wheel has 64 teeth, set the Period mode
divider prescaler to 64 and the unit displays rate in revolution/min.
Gated mode is for high speed electronic inputs and will measure frequency up to 50kHz.
NOTE: Positioning of the decimal point allows the user to display Period or Gated
measurements in chosen engineering units. A 100Hz frequency will show as 100 when
there is no decimal point but as 1.00 if two places of decimals are selected.
OPERATING
To toggle the display between the totaliser count and the Period mode rate measurement,
press the Reset button on the front panel. (Totaliser is not operating in Gated Mode).
• To Reset the totaliser count to zero press Reset and hold it for 3 seconds.
• The Reset function can be disabled in the programming sequence.
CONNECTIONS (page 3)
The unit is supplied with a standard 5-pin plug with 24cm flying leads attached. When
using contact closure as the device's input source it is necessary to use the Low Speed
input because this is the only input incorporating de-bounce circuitry.
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