DATA PRECISION 5740 - Measuring Frequency

72-1002
Model 5740 COUNTER
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MODEL 5740 OPERATING CONTROLS AND INDICATORS
REF.
NAME/DESIGNATION
DESCRIPTION g FUNCTION
1.
INPUT
BNC Connector. Connects input signal to
be measured
2 .
ATTEN
Two-position slide switch attenuator
control. Inserts X20 or XI attenuation
of input signal.
3.
MODE
Two-position slide switch. Selects 2 of
4 modes of operation: FREQUENCY/SEC
ONDS or PERIOD/EVENTS
4.
OVERFLOW
Indicator light in MSD display. When ON
indicates count greater than 9,999,999
5.
GATE
Indicator light in display. When ON in
dicates an input is gated into counter.
6.
Display
Seven decimal digits and four decimal
point positions 0.5" LED display.
7 .
Automatic-Manual
Counter Gate Con
trol
Eight position rotary switch. Turns OFF
instrument (fully clockwise). Selects
one of four averaging intervals in auto
matic modes (FREQUENCY or PERIOD); es
tablishes RESET-COUNT-HOLD sequence for
manual measurement modes.
8 . TRIGGER
Potentiometer control adjusts Schmidt
Trigger firing level to permit measure
ment of low duty cycle input signals.
9 .
Handle
Carrying handle. Also serves as tilt
stand for bench operation.
10. Line Cord
Attached 3-wire line power cord. ElA-
type plug.
11. Fuse
l/'+-3mp slow blow fuse in series with
primary power input.
12 . P.C. Board Connector
Used in BCD option.
2.3 MEASURE FREQUENCY
2.3.1 General
In FREQUENCY mode of operation, the
Model 5740 counts axis crossings of the
pulse train derived from the input signal
for a selected time interval (as deter
mined by the rotary knob setting of Gate
Time). The decimal point is automatically
positioned accordingly so that the display
is direct reading in kilohertz.
2.3.2 Step-by-Step Procedure
a) Operate MODE switch to the SEC•FREQ
position.
b) Operate the rotary switch to IS time
base.
c) Connect input to BNC connector.
d) Operate ATTEN switch to appropriate
position for expected magnitude of input
signal. (For inputs less than 40V, oper
ate ATTEN to XI. )
COPYRIGHT 197S DATA PRECISION CORPORATION. PRINTED IN THE U.S.A.
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