Modes Of Operation; Remote Displays; Connections; Latched Operation - Racal Instruments 9901 Maintenance Manual

(2)
Slacken
off the
cable clamp on
the
metal cover on
the
cable of
the flying
lead,
and push the cover
away
from the connector.
(3)
Plug the flying lead
connector
Into the
Data Output edge connector
in the
counter, noting the
keyway which
ensures correct orientation.
(4)
To minimise
r.f.
radiation interference, the metal cover
on
the cables
(4)
should
be placed over
the
edge connector and
held
into
place by
the two
screws
which
originally secured the
cover
plate
removed
in (1),
The
cable
clamp
should then be tightened.
(5)
Connect
the interface unit
to
the
data processing equipment
via the fixed
50-way
socket.
REMOTE
DISPLAYS
MODES
OF OPERATION
Connections
8.
If
the interface
is
required
to
drive a
remote
display, or such other equipment
that
does not require the data
to
be held
for
a period longer than
the
gate time, check
the following pin conditions
on
the
50-way
connector:-
Pin
No
.
Required Connection
19
Must
be
either
open
circuit
24
or
connected
to
OV.
49
Latched Operation
9.
The
display
is
latched
and
is
updated
at the
end
of
each
gate time,
irrespective of
the counter
function.
Unlatched Operation
10.
(1)
if
the interface Unit
is
connected
to
a
genuine remote
display the subjective
result
is
that the display
will
appear
to
follow the counter
,
for
both latched
and
unlatched
counter modes.
(2)
The
data outputs
will
be updated every 3
to
4
ms.
(3)
The
blue wire
'H'
on
the
28-way
flying lead
connector
should be disconnected
and
reconnected
to
'F'
together with the
violet wire. For other applications
refer to paras
16
to 18.
USING EQUIPMENT WHICH
PROVIDES
HOLD
SIGNALS
1 1
.
Differing instructions
apply,
depending on whether
the counter
is
a frequency meter
or
universal counter
timer
(UCT)
as
described
in paras 12
to 15.
Sectin
4
:
99
Series.
Appendix
1
.
Page
App
.
3