DATA PRECISION 5740 User manual

72-1002-C
Instruction Manual
for
MODEL 5740
MULTIFUNCTION COUNTER
Specifications
Operation
Theory of Operation
Maintenance
Parts Lists
Schematics
qi
IDATA PRECISION

72-1002 Model 5740 COUNTER
COPYRIGHT 1975
DATA PRECISION CORPORATION
PRINTED IN U.S.A.
Second Edition - March 1977
PROPRIETARY NOTICE
The information contained in this publication is
derived in part from proprietary and patent data
of the Data Precision Corporation. This informa
tion has been prepared for the express purpose of
assisting operating and maintenance personnel in
the efficient use of the Model 5740 Multifunction
Counter, and publication of this information does
not convey any rights to reproduce it or to use it
for any purpose other than in connection with the
installation, operation, and maintenance of the
equipment described herein.
COPyRIGHT 1975 DATA PRECISION CORPORATION PRINTED IN THE US.A.

72-1002
Model 5740 COUNTER
CONTENTS
1. INTRODUCTION
1.1 General
1.2 Specifications
2. OPERATION S CALIBRATION
2.1 General
2.2 Controls £ Indicators
2.3 Measure Frequency
2.3.1 General
2.3.2 Step-by-Step Procedure
2.U Measure Period
2.4.1 General
2.4.2 Step-by-Step Procedure
2.5 Totalizing Events
2.5.1 General
2.5.2 Step-by-Step Procedure
2.6 Stopwatch
2.6.1 General
2.6.2 Step-by-Step Procedure
2.7 Ontions
2.7.1 BCD Outputs
2.7.2 BCD Interfacing
2.7.3 Remote STOP/STOP
2.7.4 External CLOCK
2.8 Calibration
2.8.1 General
2.3.2 Step-by-Step Procedure
3. PRINCIPLES 6 THEORY OF OPERATION
3.1 General
3.2 Simplified Block Diagrams
3.2.1 Measuring FREQUENCY
3.2.2 Measuring PERIOD
3.2.3 Counting Time Increments
(SECONDS)
3.2.4 Totalizing EVENTS
3.3 Gating Controls
3.3.1 Counter Gate
3.3.2 Divider Gate
3.4 Counter-Latch-Display Controls
3.4.1 Intercycle Control
C Repetitive)
3.4.2 Manual Control
3.5 Input Signal Conditioning
3
3
3.8
3.9
6 Time Base Generation
7 Programmable Divider
8 Counter Gating
3.8.1 Counter Gate
Intercycle Control
3.9.1 Repetitive Measurement
3.9.2 Manual Measurement
10 Counter-Latch-Overflow
11 Display
3.12 BCD Option
MAINTE5JANCE
4.1
4.2
General
4.1.1 Technician Qualification
Trouble-Shooting Strategy
4.2.1 Overall Flow Diagram
4.2.2 Display Symptoms
Test Equipment
Overall System Performance Check
4.4.1 General
4.4.2 Set-Up
Power Supply Check
4.5.1 General
4.5.2 Procedure
Crystal Time Base Check
Counter-Latch-Display Check
4.7.1 Set-Up
4.7.2 Procedure
Input Signal Conditioning, Pro
grammable Divider, and Decimal
Point Check
4.8.1 Set-Up
4.8.2 Procedure
5. PARTS LISTS
5.1 Display Assembly
5.2 Main Assembly
6. REFERENCE SCHEMATICS
6.1 Main PC Board
6.2 Display
6.3 BCD Option
4.5
4.6
4.7
4.8
ILLUSTRATIONS
2-1 Model 5740 Front Panel Controls and Indicators
2-2 Model 5740 Rear Panel
3-1 Model 5740 FREQUENCY Measurement Simplified Block Diagram
3-2 Model 5740 PERIOD Measurement Simplified Block Diagram
3-3 Model 5740 SECONDS Measurement (STOPWATCH) Simplified Block Diagram
3-4 Model 5740 EVENTS Totalizing Simplified Block Diagram
3-5 Model 5740 Input Signal Conditioning, Schematic
3-6 Model 5740 Programmable Divider, Schematic
3-7 Model 5740 Counter Gating, Schematic
3-8 Model 5740 Intercycle Control, Schematic
3-9 Model 5740 Intercycle Control, Timing Waveforms
3-10 Model 5740 High Speed LSD Timing Waveforms
4-1 Overall Trouble-Shooting Flow Diagram
4-2 Power Supply Trouble-Shooting Strategy and Test Sequence
4-3 Model 5740 Main PC Board Assembly Test Points and Components
4-4 Crystal Time Base Check Test Sequence
4-5 Input Signal Conditioning 6 Decimal Point Test Sequence
4-0 Input Signal Conditioning £ Attenuator Test Check
4-7 Programmable Divider Test Sequence
4-8 Intercycle Control Test Sequence
COPYRIGHT 1975 DATA PRECISION CORPORATION. PRINTED IN THE USA.

72-1002
Model 5740 COUNTER
-6
Frontispiece. Model 5740 Multifunction Counter
COPYRIGHT 1975 DATA PRECISION CORPORATION PRINTED IN THE U.S.A.

72-1002
Model 5740 COUNTER
1
INTRODUCTION
1.1 GENERAL
Data PrecisionModel 5740 Multi-Function
Counter is a medium-frequency, seven deci
mal-digit display unit, capable of opera
ting in any one of four measurement modes.
The Model 5740:
1) Measures frequencies of repetitive
signals from 5Hz to lOOMHz.
2) Measures periods from 0.5usec to
0 . 2 sec.
3) Measures time intervals from 0.01
sec to 99 , 999.99sec, and displays five
integral decades and two decimals of the
total.
9) Provides a front-panel trigger level
control to adjust threshold of axis cross
ings for low duty-cycle, offset, and AM-
modulated inputs.
10) Incorporates a built-in hysteresis
so that noisy input signals may be mea
sured accurately.
11) With BCD option installed, provides
four-line BCD (1-2-4-8) output data for
each of the seven digits, decimal point
location, and counter status signals for
remote display, recording, or data pro
cessing applications. Also includes re
mote START-STOP control for Time measure
ments .
4) Totalizes events from one to
9,999,999 and displays seven full decades
of that total.
5) Provides four selectable time in
tervals from O.Olsec to lOsec over which
to average the measured frequency.
6) Provides four selectable multiples
from 1 to 1000 of the number of cycles
over which to average the measured period,
7) Automatically positions the display
ed decimal point to obtain direct readout
of kilohertz (Frequency measurement),
microseconds (Period measurement), hun-
dredths of seconds (Time interval measure
ment), or units (Events measurement).
8) Makes its measurements with signal
inputs as low as lOmV RMS (sine wave) or
30mV peak (pulse), with duty cycles as low
as 10% of CW or AM modulated signals.
12) Has optional provision for intro
ducing high precision external crystal-
controlled time base in addition to the
internal, aged-crystal controlled time
base circuit.
The instrument is self-contained in
one portable case only 3-1/2" high by
8-1/2" wide by 7-1/4" deep, with a car
rying handle that doubles as a tilt
stand. A three-wire line power cord is
integral with the unit, and the power
line is protected with a rear-panel ac
cessible line fuse. All operating con
trols, indicators, and input connec
tions are front-panel mounted.
Each instrument is designed for one
of the standard 115 or 230V, 47 to 430
Hz power mains, and the particular
source for which the instrument is
wired as it leaves the factory is shown
on the rear panel label.
COPYRIGHT 1976 DATA PRECISION CORPORATION. PRINTED IN THE US.A.
11

72-1002
Model S740 COUNTER
1.2 SPECIFICATIONS
1.2.1 Mode Performance
jj
c
o
B
0)
u
3
cn
>1
o
c
<D
0)
U
Ranges: Sinewave:
Pulse:
Gate Times/Resolution:
5Hz to lOOMHz
0 pps to 100,000,000 pps
(Double Pulse Resolution: 15 nanosec. between
consecutive pulses)
.01 sec/lOOHz
.1 sec/ lOHz
1 sec/ iHz
10 sec/0.iHz
Accuracy: ±1 count ± time base uncertainty
Readout: Directly in Kilohertz (7 decimal digits)
c
(1)
B
C
u
3
W
c
s
•H
<u
0.
Ranges: Sinewave: 0.5 to 200,000.0 ^sec. (5Hz to 2MH2)
Pulse: 0.5 to 9,999,999 psec. (0 pps to 2,000,000 pps)
(Max. Resolution: 1 nanosec.)
Periods Averaged/
Resolution:
Accuracy:
Readout:
1/ 1 usec.
10/ 0.1 usec.
100/ 0.01 usec.
1000/0.001 usec.
Trigger Uncertainty ('^ 20 nanosec.)
No. of Periods Averaged
Directly in microseconds.
+ time base uncertainty
±1 count
.j c
c -H
0) N
>
W
IB
■P
o
Eh
Ranges:
Signal:
Sinewave:
Pulse:
0 to 9,999,999 to Overflow
(counting continued after overflow)
5Hz to 2MHz
0 to 2M pps
x: B p
o "O c
P B u
g o e
S u 0)
a o El
o W 3
P U)
cn Id
Ranges:
Resolution:
0 to 99,999.99 seconds (27.78 Hrs.)
0.01 seconds
1-2
COPYRIGHT 1975 DATA PRECISION CORPORATION PRINTED IN THE U.SA.

72-1002
Model 5740 COUNTER
1.2.2 Instrument Performance
Time Base
Type:
Frequency:
Uncertainty:
Stability:
Temperature:
Power Supply
Sensitivity:
Warm-up Time:
High-Stability Crystal
lOMHz
±0.1 ppm. Field adjustable
±0.01 ppm/sec. (Jitter)
±0.6 ppm/month
±4.0 ppm/year
±5 ppm, oven
0°C to 40°C
<0.1 ppm at all modes
< 10 minutes to rated performance
Input Characteristics
Coupling:
Impedance:
Sensitivity
(@ xl Atten):
Trigger Level:
AC (RC:i<0.05 seconds)
1 Megohm || 25pf (Input 2V @ xl Atten)
68 kilohm (Input 2V @ xl Atten)
Sinewave: lOmV RMS 5Hz to 20MHz linearly
to 50mV RMS (? lOOMHz
Pulse: 30mV p-p @ .25 nanosec. width
linearly to 150mV p-p @ 7.5 nanosec.
width
Rise Time: for adequate sensitivity after RC=
0.05 sec. coupling
Dwell Time: > 200 nanosec. (Period)
5 nsec. (Freq. , Events)
Adjustment Range @ xl Atten = ±0.5V
@ x20 Atten = ±10V
Maximum Inputs w/o Damage:
Sinewave:
Pulse:
DC to 50KHz: 250V RMS
50KHz to lOOMHz: V x F Product =
12.5 x 10^ (Or 5V, whichever is the greater)
Peak AC + DC 500V
(AC component limited as above)
Display
7 LED decimal digits, 0.43" high
5 LED decimal point
2 LED Annunciators (Gate, Overflow)
COPYRIGHT 1975 DATA PRECISION CORPORATION. PRINTED IN THE US.A.
13

72-1002 Model S740 COUNTER
Power, Physical, Environmental
Powers 115V, 50/60Hz, or 230V SO/SOHz, factory connected;
12 Watts
Dimensions: aS" H x W x 7-3/4" D (without handle), or 89cm x
216cm X 185cm
Weight: 6"! lbs. (shipping), 5 lbs. (net); or 2.27)cg or 2.951cg,
respectively
o o
Operating Temperature: 0 C to 40 C
Storage Temperature: -25°C to +75°C
Humidity: 0 to 80% RH, non-condensing.
1-4
COPYRIQHT 197B DATA PRECISION CORPORATION PRINTED IN THE US.A.

72-1002
Model 5740 COUNTER
OPERATION
2.1 GENERAL
Data Precision Model 5740 Electronic
Counter is operated using clearly marked
front panel controls and indicators.
Displayed values are read out directly
in engineering units of kilohertz and
microseconds, and annunciator lamps in
dicate counter OVERFLOW and GATE opera
ting status.
Remote display of data, counter status,
gate status and user control signals
(e.g. printer enable) are available from
the rear panel connector when the BCD
option is factory installed.
Any or all options may be installed in
any one Counter configuration.
Power source for the Model 5740 Counter
may be either of two universally standard
levels, ... 115 or 230, (47 to 63Hz), and
each instrument is factory wired for the
nominal voltage expected in the area in
which the instrument is to be shipped.
See Paragraph for instructions to modi
fy the connections if required for other
local conditions.
2.2 CONTROLS AND INDICATORS
Figure 2-1 locates and identifies Model
5740 front panel controls and indicators.
Figure 2-2 locates and identifies Model
5740 rear panel features.
Table 2-1 describes these controls and
indicators and their COUNTER functions.
- BEFORE YOU OPERATE YOUR MULTIFUNCTION COUNTER -
The Model 5740 Multifunction Counter is shipped in a pro
tective fitted plastic container. This manual is packed
in its own wrapper and is placed outside the container.
It should be read very carefully before operating the
counter.
Your shipment should contain:
(1) One Model 5740 Multifunction Counter, with attached
line cord and power fuse
(2) Certificate of Conformance
(3) Warranty Card
(4) Authenticated Factory Acceptance Test Data Sheet
(5) One Instruction Manual, containing information
of Specifications, Operating Instructions, Theory
of Operation, Maintenance, Parts Lists, and Ref
erence Schematics.
Inspect the packing case and the instrument for any signs
of damage during shipment; report immediately to the car-
rier if any apparent damage.
COPYRIGHT 1975 DATA PRECISION CORPORATION. PRINTED IN THE US.A.
2-1

72-1002
Model 5740 COUNTER
♦ Ci»ac
5740
/\S
■>s
nitr
V to u > 90i 1 0
1
, .
(j«OATAy I
TZZI
Lzr
:y
Fig. 2-1. Model 5740 Front Panel Controls and Indicators
Fig. 2-2. Model 5740 Rear Panel
2 2
COPYRIGHT 1975 DATA PRECISION CORPORATION PRINTED IN THE U.S.A.

72-1002
Model 5740 COUNTER
Table 2 1
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.
2 3

72-1002 Model 5740 COUNTER
e) Set TRIGGER LEVEL for stable values
on display. (Start with knob indicator at
zero, or midposition.)
f) Observe OVERFLOW indicator. If ON,
operate rotary switch to select lower val
ue gate time of O.lsec. If OVERFLOW re
mains ON when gate time is O.IS, then in
put signal is above lOOMHz specification
limit.
If OVERFLOW is OFF, and if greater
resolution is desired, operate rotary
switch to increase gate time to lOS posi
tion. In this position, measurement will
be repeated in 10.3 seconds, and least
significant digit will indicate O.lHz in
crements .
g) Read display directly in kilohertz
when value is stable. Table 2-2 summa
rizes the operation of the Model 57U0 for
different control settings in measuring
two frequency input signals.
2.4 MEASURE PERIOD
2.4.1 General
In PERIOD Mode, the Model 57it0 counts
time increments for a number of pulses
determined by the axis crossings of the
input signal and as selected by the op
eration of the front panel rotary switch.
The decimal point is automatically po
sitioned so that the displayed period or
average period value may be read direct
ly in microseconds.
2.4.2 Step-by-Step Procedure
a) Operate the MODE slide switch to
PERIOD-EVENTS.
b) Operate rotary switch to 100 (100
periods to be averaged.)
Table 2-2
MODEL 5740 FREOUENCY MEASUREMENT PARAMETERS
Input
GATE TIME Settling
Display
Display*
Frequency Time Gate is open
Resolution
Overflow
MHz
(LSD)
10 sec
.IHz ON
231+. 5678
1 sec
IHz OFF
1231+. 567
1.231+5678
. 1 sec
lOHz OFF
01231+. 56
.01 sec
lOOHz OFF
001234.5
10 sec
. IHz
ON
999.9900
99.999990
1 sec
IHz
ON
9999.990
100 msec
lOHz
OFF
99999.99
10 msec
lOOHz OFF
099999.9
*For greatest resolution, use Time Base setting for minimum number of
leading zero's without OVERFLOW.
2-4
COPYRIGHT 1975 DATA PRECISION CORPORATION PRINTED IN THE U5.A.

72-1002
Model 5740 COUNTER
Table 2-3
MODEL 5740 PERIOD MEASUREMENT PARAMETERS
Input Period No. of Input
Resolution Overflow
Micro-
Cycles Gate Was
(LSD) Light
Display*
Seconds
Open
»
123456.GO
1
1 us
OFF
G123456
IG
. 1 us OFF 123456.G
^8.IHz
IGG .01 us
ON
23456.00
IGGG
.GGl us
ON
3456.GOG
^Select resolution position for non-overflow reading with minimum
leading zero's.
c) Connect input to BNC connector.
d) Operate ATTEN to appropriate posi
tion for expected magnitude of input
signal. (For inputs less than 40V,
ATTEN = XI.)
e) Set TRIGGER LEVEL for stable val
ues on display. (Start with knob indi
cator at zero, or midposition.)
f) Observe OVERFLOW indicator. If ON,
operate rotary switch to select lesser
number, 10, of periods to be averaged;
if OVERFLOW is still ON, rotate switch
to select least number, 1, of periods to
be averaged. If still in OVERFLOW,
Period is greater than 9 , 999,999usec (or
10 sec), and if sine wave, then input is
not within specified value.
g) Read display directly in micro
seconds, when displayed value is stable.
Table 2-3 summarizes the operation of
Model 5740 for different control set
tings when measuring an input period
corresponding to approximately 8Hz.
2.5 TOTALIZING EVENTS
2.5.1 General
In the EVENTS mode of operation, the
Model 5740 counts axis crossings of the
input signal over a time interval deter
mined by the manual operation of the
front panel rotary control knob (or by
electrical control signals when the BCD
option is installed).
2.5.2 Step-by-Step Procedure
a) Operate MODE switch to PERIOD-
EVENTS position
b) Operate Rotary switch to RESET
position
c) Connect input to BNC front-panel
connector
d) Operate ATTEN switch to appropriate
position for expected input amplitude.
(For inputs greater than 40 volts, op
erate ATTEN to X2G.)
e) Operate Rotary switch to SEC-EVENTS
position. The GATE light comes ON and
remains ON while counting events.
f) Observe counted value as displayed.
If the displayed values appear to be
much more erratic than expected, then
operate TRIGGER LEVEL control to stabi
lize the counting.
g) To stop the counting, operate the
Rotary switch to the HOLD position.
h) To continue the counting from the
previously held value, operate the Rota
ry switch to the SEC-EVENTS position.
i) To start a new events totalizing
cycle begin with Step b) above.
COPYRIGHT 1975 DATA PRECISION CORPORATION. PRINTED IN THE U.S.A.
26

72-1002
Model 5740 COUNTER
2.6 STOPWATCH
2.6.1 General
In SECONDS mode of operation, the Model
5740 is used as a STOPWATCH and counts
time in increments of 0.01 seconds for an
interval under manual control via the
front panel rotary switch or by electrical
control signals when the BCD option is in
stalled. The displayed value is read out
directly in seconds (to 0.01 sec resolu
tion); the decimal point is correctly po
sitioned on the display.
2.6.2 Step-by-step Procedure
a) Operate MODE slide switch to SEC'FREQ
position.
b) Operate the rotary switch to RESET.
This action resets the display to 00000.00.
GATE Light goes OUT after display is reset.
c) To start timing, operate Rotary
switch to SEC'EVENTS. GATE light-comes ON
and remains ON, while the least signifi
cant digit increments at 100 per second
rate.
d) To stop timing, operate rotary knob
to HOLD. GATE light goes OUT and display
value remains at last count.
e) Read time in seconds. Maximum value
is 99,999.99 seconds, or 27.8 hours, up to
appearance of OVERFLOW. It greater time
interval is to be counted, make note of
number of counter display overflows and
extend reading accordingly. For example,
if there has been one OVERFLOW, the maxi
mum value will be 199,999.99 seconds.
(The OVERFLOW annunciator remains ON from
moment of first OVERFLOW.)
f) To continue STOPWATCH action from
the held count, operate Rotary switch to
SEC-EVENTS position.
g) To start new STOPWATCH timing cycle,
operate Rotary switch to RESET as in Step
b) above.
value, operational status, and control
circuitry. Terminal designations for
the 44-pin edge connector are identified
in Table 2-4. Note that two signals are
used to identify the four operating
modes, and combinations of these two for
each operating mode are shown in Table
2-5.
2.7.2 BCD Output Interfacing
a) Data outputs are parallel, BCD (1,
2,4,8) and DTL/TTL compatible.
Logic "1" > -t-2.4V
Logic "0" < 0.4V sink for 4mA
Fanout for 2TTL loads
b) Status as identified by the termi
nal nomenclature is indicated by a high
level (Logic "1").
2.7.3 Remote START/STOP
When the optional provision for Remote
START/STOP is installed, the user may control
the Counter action by applying a DTL/TTL low
level or ground signal to the designated
rear panel connector terminals as identified
in Table 2-4.
NOTE: The remote control of the Counter
must be activated ONLY when the Counter is
in the SEC/EVENTS counting operation.
If in FREQ or PERIODS AVGD Mode, applying
a remote control signal will stop or reset
the counting in process.
a) Select SEC-EVENTS operation at the
front panel.
b) Obtain the desired Counter perfor
mance by applying digital logic levels in
accordance with the table below.
Counter
Operation
RESET
HOLD
RESET
"0"
" 1 "
COUNT
"1"
M 2 IT
HOLD
»»2»»
"0"
"0" = Ground or <'2.5VDC or disconnected
"1" = 3.5V-HVDC
2.7 OPTIONS
2.7.4 Extarnal CLOCK
2.7.1 BCD Outputs
When BCD option is installed, internal
circuits are modified and the main PC-
board terminals are connected to counter
2-6
When the optional provision for External
CLOCK is installed, the Model 5740 rear
panel is modified to incorporate a BNC
connector and switch. To use the external
clock feature, an accurate oscillator
of 10 MHz should be available.
COPYRIGHT 1975 DATA PRECISION CORPORATION PRINTED IN THE US.A.

72-1002
Model 5740 COUNTER
a) Connect the external 10 MHz CLOCK
to the rear-panel BNC connector.
b) Operate the rear panel selector switch
to EXTERNAL.
NOTE: The internal clock remains ins, .v lied
in this option, and the user may switch
to the internal clock by operating the rear
panel switch to INTERNAL.
2.8 CALIBRATION
2.8.1 General
The Model 5740 COUNTER time base uti
lizes a crystal-controlled oscillator
whose frequency is adjustable over a
very narrow range by capacitor C12. If
a very accurate frequency standard is
available (better than .Olppm) it may be
used to calibrate the Model 5740 COUNT
ER, using the procedure detailed in the
next paragraph.
2.8.2 Step-by-Step Procedure
a) Allow 30 minute warm-up.
b) Set up the frequency standard for a
signal near full scale range of the COUN
TER: lOMHz on IHz resolution scale. Con
nect to COUNTER INPUT, i.e., use frequency
of approximately 1, 10, or lOOMHz.
c) Set up COUNTER for FREQUENCY Mode,
select 1 sec gate time.
dj Remove top cover of the COUNTER;
locate trim capacitor C12 (See Figure
4-3).
e) Adjust C12 until measured value is
equal to the frequency standard and results
in 0000.000 display plus overflow indica
tion.
f) Remove standard; close cover; unit
is recalibrated.
Table 2-4
OPTIONS: BCD & Remote START/STOP
CONNECTOR DESIGNATIONS
n
D4B1 ' 1
D4B2 ' 2
D4B4 [ 3
D4B8 4
PRINT ENABLE | 5
A ] D1B4
B D1B2
C 1 DlBl
D , D1B8
E ' DPI
1
1
D5B1 , 6
D5B2 i 7
D5B4 8
D5B8 ' 9
lio
F ' DP5
H 1 DP4
J ' DP3
K 1 DP2
L D2B2
1
1
|11
MODE(I) 12
D6B1 '13
D6B2 |14
D6B4 'l5
1
M , D2B1
N 1
P '
R 1 MODE(I)
S 1 D3B8
D6B8 |16
RESET* 17
D7B1 '18
D7B2 |19
D7B4 20
D7B8 |21
GND 2 2
1
T ' D3B4
U ' D2B4
V ' D2B8
W 1 D3B1
X D3B2
Y 1 OVERFLOW
Z ' HOLD*
1
Note See Table 2-5 for Mode status
decoding.
*Active only when the Remote START/STOP
is installed
Table 2-5
DECODING MODEL 5740 OPERATING MODE SIGNALS
TERMINAL 12
QC
0
1
Z
s
0 FREQUENCY
SECONDS
LU
1 PERIOD
EVENTS
"0" = Ground level; OV, nominal
"1" = +SV, nominal
COPYRIGHT 1975 DATA PRECISION CORPORATION. PRINTED IN THE U.S.A.
27

72-1002
Model 5740 COUNTER
CALIBRATION RECORD
DATE
BY
COMMENTS
DATE
BY
COMMENTS
NOTES
CHANGING POWER SOURCE CONNECTIONS
The connections for power source voltage (lOOV,
115V, or 23CIV) are made on the Terminal Board CTBl)
mounted on the inside of the rear panel, and through
which the power source is switched to the appropriate
input transformer tap. The table below defines the
TBl terminals to which the lead from Switch 1-B
should be connected for the designated power source.
The illustration at the right may be used to help
identify the correct wire lead.
POWER
SOURCE
lOOVAC
115VAC
230VAC
CONNECT
Sl-B to
TBl-S
TBl-4
TBl-3
-MOUNT L2 TO
S/Dc
re/
TB!
(MOUNT£C> ON PjAN£L)
28
COPVRIOHT 1t7B DATA PRECISION CORPORATION PRINTED IN THE U.S>.

72-1002
Model 5740 COUNTER
3.1 GENERAL
THEORY
and
PRINCIPLES of OPERATION
The Model 5740 MULTIFUNCTION ELECTRONIC
COUNTER comprises a counter-latching
register-display chain, an input signal
conditioning circuit, a crystal-controlled
time base, programmable digital control
circuitry, and the necessary regulated and
filtered power supplies. Operation of two
front panel switches sets up the instru
ment for one of four measuring modes. The
5740 :
Measures FREQUENCY of Input Signal in
Kilohertz
Measures PERIOD of Input Signal in
Microseconds
Counts Time in SECONDS
Totalizes EVENTS in Units
Operation of the instrument for each
function is explained with the aid of sim
plified block diagrams for each function.
Complete schematics are reproduced and
bound in the rear of the book and should
be referenced when the theory of operation
of each module of the instrument is de
scribed .
3.2 SIMPLIFIED BLOCK DIAGRAMS
3.2.1 Measuring FREQUENCY
As shown in Figure 3-1, when slide
switch S4 is in the SECONDS/FREQUENCY po
sition, the input signal is gated to the
Counter-Latch-Display chain, and the IMHz
time base is gated to the Programmable
Divider. The selected position of rotary
switch S3 sets up the divider for a GATE
TIME base of 10msec, 100msec, Isec, or
lOsec, while simultaneously positioning
the decimal point in the display to the
appropriate decade.
INPUT
SIGNAL
CONDIT
MODE
COUNT
GATE
GATE
Tf
S F -4 4 « ^
10
1 1
MHZ
MHZ
MODE
GATE
PROGRAM.
DIVIDER
GATE TIME
"n
S3 I SYNCH START MEASURE
INTERCYCLE
CONTROL
T
Fig. 3-1. Model 5740 FREQUENCY Measurement Simplified Block Diagram
COPYRIGHT 197S DATA PRECISION CORPORATION. PRINTED IN THE U5.A.
3 1

72-1002
Model 5740 COUNTER
In operation, input signals of sine
waves or pulse trains are converted to a
TTL compatible pulse train by the input
signal conditioning circuitry and gated to
the counter by control signals from the
intercycle control circuitry. The Pro
grammable Divider operates on the gated
IMHz time base and counts down according
to the selected GATE TIME.
At the end of the selected GATE TIME
interval, the Intercycle Control Circuit
ry removes the enabling level from the
Counter Gate, thereby stopping the count
er. At the same time, a three-step
counter in the Intercycle Control gener
ates control signals to:
1) Transfer the value from the Count
er to a Latching Register which automat
ically updates the Display,
2) Reset the Counter in preparation
for the next conversion cycle and,
3) Initiate the next conversion cycle
by enabling the counter gate.
The sequence of control actions is ac
complished in approximately 0.3 sec.
3.2.2 Measuring PERIOD
As shown in Figure 3-2,
switch S4 is moved to the
tion, the input signal is
Programmable Divider and
base pulse train is gated
er-Latch-Display. Rotary
used to select the number
input signal counted down
when slide
PERIOD posi-
gated to the
the IMHz time
to the Count-
switch S3 is
of periods of
before trans
mitting a control indicator to the
Intercycle Control circuitry. The
Counter Gate is enabled for a selected
number of input signal transitions
(Periods) under control of the Inter
cycle Control circuit. As before, the
Intercycle Control circuitry steps the
value from the Counter to the Latch and
thence to the Display, and sequences the
circuit through RESET and the start of
the next measurement cycle. The inter
val between such measurements is simi
larly approximately 0.3 sec.
3.2.3 Counting Time Increments (SECONDS)
As shown in Figure 3-3, when slide
switch 84 is placed in SECONDS opera
tion, the IMHz time base signal is gated
into the Programmable Divider which, in
turn, is programmed to divide by 10,000,
so that a timing signal pulse train of
0.01 seconds interval is developed at
its output and connected to the Counter
Gate. The Counter Gate is controlled by
the action of rotary switch S3 which by
passes the Intercycle Counter program
ming control. At all times the Counter
output is transferred to the Latching
register and continuously updates the
Display.
The Divider-to-Counter Gate is enabled
whenever Switch S3 is in the SEC/EVENTS
position, permitting the time increments
to accumulate. When S3 is placed in the
HOLD position, the enable level is removed
from the Counter Gate, and the count value
remains. Returning S3 to the SEC/EVENTS
position restores the enable level to the
Counter Gate and the value in the counter
H
INPUT
MODE
SIGNAL
GATE
CONDIT
10
1
MHZ MHZ
MODE
GATE
COUNT
GATE
PERIODS AVGD
» ^ 1 RESET
71 .
PROGRAM.
INTERCYCLE
DIVIDER
CONTROL
SYNCH START MEASURF
Fig. 3-2. Model 5740 PERIOD Measurement Simplified Block Diagram
3-2
COPYRIGHT 1975 DATA PRECISION CORPORATION PRINTED IN THE US.A.

72-1002
Model 5740 COUNTER
INPUT
SIGNAL
CONOIT
MODE
GATE
T
COUNT
GATE
S-F -♦ 4
10
1
MHZ
MHZ
MODE
GATE
S3
RESET \/j~-
SEC/EVENTS
HOLD
PROGRAM.
DIVIDER
INTERCYCLE
CONTROL
Fig. 3-3. Model 5740 SECONDS Measurement (STOPWATCH) Simplified Block Diagram
INPUT
SIGNAL
CONDIT
h
MODE
GATE
10 h
MHZ
MHZ
^
r
MODE I
^ GATE I
COUNT
GATE
GATE I 1
RESET
SEC/EVENTS
HOLD
PROGRAM.
DIVIDER
I
r
INTERCYCLE
CONTROL r
I I
I
i l J l
Fig. 3-4. Model 5740 EVENTS Totalizing Simplified Block Diagram
increases at the 100/sec rate from its
previous value. Or the value can be re
set to zero at any time by positioning the
Rotary Switch to RESET position.
3.2.4 Totalizing EVENTS
As shown in Figure 3-4, when slide
switch S4 is placed in the SECONDS/EVENTS
position and rotary switch S3 is in any of
the three manual positions, the input
pulse train of events is gated to the Pro
grammable Divider, which, in turn, is set
up to divide by 1, thereby providing a
pulse output for every event pulse input.
As in STOPWATCH Operation, the COUNTER
output is continuously transferred by the
latching register and thence to the Dis
play.
The rotary switch is operated manually
in the same way as in the SECONDS Mode,
enabling the Counter Gate when in the SEC/
EVENTS position, holding the total count
when in HOLD, resuming the totalizing
count when returned to the SEC/EVENTS po
sition, and resetting to zero at the RESET
position.
3.3 GATING CONTROLS
As described in the previous paragraphs,
the functions of the Model 5740 instrument
are accomplished by internally programming
the Counter and Divider according to the
function selected by the combined settings
of slide switch S4 and rotary switch S3.
COPYRIGHT 1975 DATA PRECISiON CORPORATION. PRINTED IN THE U.S.A.
33

72-1002
Model 5740 COUNTER
A summary of the front panel control ma
trix is shown in Table 3-1 below.
3.3.1 Counter Gate
The Counter Gate is programmed to select
one of three inputs:
Conditioned Input (FREQUENCY MODE)
IMHz Time Base (PERIOD MODE)
Divider Output (.01 sec increments in
(SECONDS MODE) and in (EVENTS MODE)
3.3.2 Divider Gate
The Programmable Divider Gate selects
one of two inputs:
Conditioned Input (PERIOD, EVENTS
MODES)
IMHz Time Base (FREQUENCY, SECONDS
MODES)
3.4 COUNTER-LATCH-DISPLAY CONTROLS
Operation of the decimal point in the
seven-digit display is also programmed
according to the function selected by
the combined settings of slide switch SU
and rotary switch S3. A summary of
these control requirements is also in
Table 3-1.
3.4.1 Intercycle Control (Repetitive Modes)
When measuring FREQUENCY of a repeti
tive input, or the PERIOD of one cycle
of such an input, the Counter-Latch-
Display sequence is programmed by the
Intercycle Control timer. At the end of
the switch-selected time base (FREQUEN
CY) or switch-selected number of periods
(PERIOD), counter control is transferred
to the Intercycle Control circuitry
which
* Removes the input to the counter
* Transfers the counter value to the
latching register, and thence to the
display
* Resets the counter to zero
3.4.2 Manual Control
When counting SECONDS, or totalizing
EVENTS, the Counter-Latch Display is pro
grammed by the RESET-SEC/EVENTS-HOLD posi
tion of rotary switch S3. The RESET posi
tion :
* Removes the input to the counter
* Resets the counter value to zero
When operated to the SEC/EVENTS position,
the control signals:
* Enable the COUNTER Gate
* Enable the transfer from Counter to
Latch to Display
Table 3-1
MODEL 5740 COUNTER GATING CONTROL
MEASURING
FUNCTION
Input To
Counter Gate
Input To
Divider Gate
Divider
Ratio
Decimal
Point Selection
FREQUENCY
Conditioned
Input
IMHz Time
Base
Selected
GATE TIME
Per
Selection
PERIOD
IMHz Time
Base
Conditioned
Input
Selected
Numbe:" of
PRDS AVGD
SECONDS
Divider
Output
IMHz Time
Base
+ 104
=0.01 sec
Interval
DP 3
EVENTS
Divider
Output
Conditioned
Input
+ 1 None
3-4
COPYRIGHT 197S DATA PRECISION CORPORATION PRINTED IN THE U.S.A.