Rear Panel - Datron 4708 User Handbook Manual

With Remote
Sense
ON,
the
output voltage
is
fed across the
1+
and
I-
terminals only,
and must be
sensed
externally,
using leads
connected
to
the
Hi
and
Lo
terminals.
Remote
Sense
is
not available
on lOOjiV
-
lOOmV
ranges.
It
is
not applicable
to
Current
outputs.
On
Ohms
ranges.
Local Sense
is
used
for
2-wire connections,
and
Remote
Sense
for 4-wire.
(Changing
FUNCTION
into Q,
forces the
4708
into
Remote
Sense, but
this
may
be
deselected
for
2-wire
operation).
The Remote
Sense
LED
always
indi-
cates the true connection:
Lit
=
Remote;
Unlit
=
Local
Guard
Terminal
The Guard
terminal
is
permanently connected
to
the
internal
guard
shields:
Remote
Guard
The Remote Guard
key
has
'toggle' action.
Successive presses
alternate
between
ON
and
OFF.
With Remote Guard OFF,
Guard
is
internally
connected
to
the
I-
terminal.
With Remote Guard ON,
the internal link to
I-
is
removed.
The Guard
terminal
can
then
be connected
externally
to
reduce
common
mode
interference.
Ground
Terminal
The Ground
terminal connects directly to the
4708
internal
Ground
shields
and
to
Safety
Ground
via the
power
cable.
Output Connections
Connections
to
the
output terminals
may
be
made
either
with
leads or via a
shrouded
connector.
For
Voltage outputs
in local
sense
the
two
leads should be
attached to the
Hi and
Lo
terminals.
Various configurations
of 4708 load connections are
detailed
in
Section
4.
REAR
PANEL
(Shown
with
alternative
Rear Ouqjut
terminals)
i
n
DATRON
INSTRUMENTS
( I I « 1
POWER
INPUT
The
recessed
POWER
INPUT
plug,
POWER
FUSE
and
LINE
VOLTAGE
SELECTOR
are located in the center
of
the
rear panel,
contained within a
single
moulded
unit.
Details
of
connections, selection of
line
voltage
and fuse are given
in
Section
2,
REAR OUTPUT
ALTERNATIVE
(Option
42)
This can be incorporated
at
manufacture,
to
provide
six
output
terminals
on
the rear
panel
instead
of
the six
on
the front.
Their
functions
and
connections
are
identical.
SOCKET
J53
(External
Reference Frequency
Input)
This
BNC
socket
is
located next
to
the
cooling
air
intake
filter.
It
may
be used
to
lock the internal
frequency
synthesizer
to
a
customer's
own
frequency
standard.
Voltage and
frequency
criteria are
given
in
Section
2.
An
on-off switch, S53,
located
above
this
socket
is
provided
to
enable
this facility. If
the switch
is
on and
an
external
frequency
is
not present, error
message
'Error
EF'
is
displayed.
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