Table of Contents
Advertisement
2.2.3
Display
and
Indieatom
The
function
of the display
and
indicators
is
described
below,
Display~The
display consists
of
a
nine
digit
mantissa
and
a
single digit
exponent.
The
exponent
uses
a
leading
minus
to
indicate
negative values.
The
sign
on
the
exponent
changes
to
+
for
zero or
positive values,
The
dimension
iS
determined
by the
exponent and
the
Hz,
SEC
or
V
indicators,
Units
Indicator,'.—
The
units are
shown
by
three
indicators,
The
Hz
indicator
is
on
during frequency
measurements
and
the
SEC
indicator
is
on
during time
and
period
measurements..
When TRIGGER
LITvn*L
button
is
pressed,
the
V
(volts)
mdicator
turns on.
GATE
]ndicator~When
the instrument takes
a
measure-
ment,
the
GATE
indicator blinks
at
a rate
which
is
pro-
portional
to
the gate time.
IEEE
Status indicators—
The
REMCTTE,
TALK
and LISTEN
indicator^;
are
used
when
programming
the
instrument
over the
IHEE-488
bus. Refer
to
Section 3
for
compieto IEEE
programming
information.
These
status indicators
are
not
operational
during
front
panel instrument
operation,
''he
tilt
bail,
which
is
located
on
the
bottom
cover
of
the
instrument,
is
useful for elevating the
front of
the
instru-
ment
to a
convenient viewing
height,
To
extend, the
bail,,
first
rotate
it
90~'
away from
the
botton'\
cover
and push
up
on
the leg
to
lock
it
into place,
To
retract
the
bail,
pull
the
leg-S
away
from
the
bottom
cover
and
then
rotate
the
bail
until
it
is
flush
with
the
bottom
cover.
2.3
REAR
PANEL
FAMILIARIZATION
Figure
2-2
shows
the rear panel layout
of
the
Model
^75,
2.3,1
Connectors and
Terminals
AC
Receptacle—
Power
is
applied
through
the supplied
power
cord
to
the 3-terminal
AC
receptacle.
Note
that
the
selected
power
supply
voltage
is
marked on
the
rear
panel
above
the
line
voltage selector switch.
IEEE«4S8
Connector—
This connector
is
used
to
connect the
instrument
to
the
IEEE-488
bus.
IEEE
interface
functions
are
marked
above
the connector.
TRIGGER
LEVEL
OUTPUT
Connector-These two
BNC
connectors
are
used
to
connect the
DC
voltage
level
from
the
trigger circuits to
an
external
DMM
or
oscilloscope.
DC
output range
is
marked
above
the connectors.
CLOCK
Connector—
This
BNC
connector
is
used
to
out-
put
the
internal
dock
as a reference to
another
instrument,
The same
input
may
be connected
to
an
external
dock
reference,
To use
an
external clock reference, the internal
time base
must
be
set for
external
operation. Refer
to
Sec-
tion 6 for
this
procedure
and
proper
signal
levels to
apply,
EXT
ARMING
&
GATE/DELAY
Connector--A
BNC
con-
nector
which
may
receive
one
of
three
signals:
arming
pulse, external gate signal
or external delay pulse. This
in-
put
is
useful
when
gate or
delay times other than
the
in-
ternal
times are required or
to
take
one
reading with
the
Model
775
in
synchronized with other equipment.
The LINE
VOLTAGE SELECTOR
switch
selects
the
line
voltage
that the
Model
775
will
operate
on. For informa-
tion
on
voltage selection
refer to
Section
6.
2.3.3
IEEE-488
Address Switches
The
IEEE-488 address switches
are
used
to
program
the
primary,
address
for
IEEE-488
interface
operation
.
The
ad-
dress
may
be
set
from 0
to 30.
2,3,4
Urn
Fuse
The LINE
FUSE
provides
protection
for
the .AC
power
line
input, For
information
on
replacing
this fuse, refer
to
Sec-
tion
6.
2.4
POWER-UP
PROCEDURE
The
basic
procedure
of
powering
up
the
Model
775
is
desciibed below,
1,
Connect
the
female
end
of the
power
cord
to
the
AC
receptacle
on
the rear panel.
Connect
the
other
end
of
the
power
cord
to
a
grounded
AC
outlet.
Advertisement
Chapters
Table of Contents
