DATA PRECISION 5740 - Stopwatch Functionality; Optional Features

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.