HP 54501A - The TV Trigger Mode

The
TV
Trigger
Mode
The
TV
Trigger
Mode
is
used for
triggering
on
clamped
television
signals.
This
mode
will
allow
you
to
select
one
of the
TV
signal
frames
and
one
of
the
lines within
that
frame.
Once
the
TV
Trigger
Mode
has
been
selected
the
Television
Signal
Standard
can
be
selected
using
the
TRIGGER:STANDARD
command.
The
three
parameters
for
this
command
are
525,625, and
USER.
Any
of
these
modes
allow
you
to
select the
source
of
the
trigger signal
and
the
trigger
level.
The
source
is
set
by
sending
the
SOURCE
command.
The
SOURCE
command
allows
the
selection
of
channel
1
through
4
using
the
command
":TRIGGER:SOURCE
CHANNEL2".
The
trigger
level
is
set
by
sending
the
command
":TRIGGER:LEVEL
<
value
>".
With
the
standard
set
to
525
or
625
the
commands
that
can
be
used
are
POLARITY,
FIELD,
and
LINE.
The
POLARITY
command can
accept
NEGATIVE
and
POSITIVE
as
its
parameters
and
sets
the edge
for
the
trigger.
The FIELD
command
uses
1
and
2
for
its
parameters
which
select
the
first
or
second
field
of
the
television
signal.
The
LINE
command
parameters are
different
for
the
two standards, refer
to
the
command to
determine
the
correct
values.
The
HOLDOFF
value
can
also
be
set
in
the
TV
trigger
mode,
as
in
all
modes.
HP
54501A
Programming
Trigger
Subsystem
16-7