Tektronix 7704A User Manual

in d icates α 100-microvolt sensitivity wit h t he CRT
dis p lay
inverte d and calibrated vertical d eflection factors . T h is
results in t he i d ealize d output current waveforms s h own in
F ig . 2-41 Β at t he column analog data output, terminal Α 37
of t h e p lug-in interface .
R esistor R 111, connected between time-slot 1
an
d
t
he
column analog d ata output, enco d es two units of current
during time-slot 1 . R eferring to t h e C h aracter Selection
M atrix, two units of column current, along with t he two
units of row current
encode
d by resistor
R
10 (row 3),
indicates
t
h
at two
zeros s houl d
be adde d to t
he
d isplay .
R esistor R 120 adds one unit of column current du ring
time-slot
2
an
d ,
along with t h e one unit of curre n
t
from
t
he
row output,
t
h e R
ea
d out System is instructe d to add
an
invert arrow to t he display . R esistor R 130 is not connected
to t h e time-slot 3 line, since t he vertical d eflection factors
are calibrate d . T h erefore, t h ere is no column current out p ut
d uring t h is time-slot and no dis p lay on t he CR T (see
Dis p lay-S k i p Generator for furt h er information)
.
Circuit Description -7704A Service
During time-slot 4, two u nits of column current are
enco d e d by R 140 .
T h
ere is no row current encode d during
t
h
is time-slot ; t h is results in t h e numeral 1 being d is p layed
on t
h
e C
R T .
N eit h er row nor column analog d ata is
enco d ed d uring time-slots 5, 6, and 7 as d efine d by t he
Stan d ar dR ead out
F
ormat . During time-slot 8, two units of
column current and t h ree u nits of row current are enco ded
by resistors R 181 an d R 80, res p ectively . T h is add resses t he
μp refix
in t h e C
h
aracter Selection
M
atrix
.
T h e final
d ata output
is provid e d from time-slot 9 by
R 190 connecte d to t h e col u mn output and R90 to t h e row
out p ut . T h ese resistors encode t h ree units of col u mn
current
an
d four units of row current to cause α V (volts) to
be d is p laye d . Time-slot 10 is not encoded in accor d ance
with
t
he Standard R
ea
d out F ormat . T he resultant C RT
rea d out will be t 100 μ V .
In t h e above exam p le, t
h
e row analog data
was
p rogrammed to define w h ic h row of t h
e
C
h aracter
Ti m e-Slot
Pu lses
f r o m
R ea d out
System
Α 29
Ε
TS'10
*Not used
in sta nd ar d format .
Β37
R ow
Analog
Data to
R ea do u t
Syste m
Col umn
Analog
Data to
R ea dou t
System
Α 37
F ig . 2-40
. Typical encod
i
n g sc he m e for voltage-se n si n g p l u g-i n u nit . Co d i n g s h own for d eflectio n facto r of 100 m icrovolts .
2- 4 9

Tektronix 7704A Specifications

General

Brand	Tektronix
Model	7704A
Category	Test Equipment
Language	English