DATA PRECISION 5740 - Instrument Calibration

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.
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