The Tv Trigger Mode - HP 54501A Programming Reference Manual

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