Block Data Transfer
Format Mode Data Transfer
The
following
paragraphs
contain
detailedinformationon
the
data
fields recognizedby
Format
mode, checks
made
on
the
fields before
data
transmission,
the
data
block
start
point,
and
the
type
of
data
transferred.
FIELDS.
The
start
point
for a field isdefinedby a
««start
field" indicator.A
««stop
field" indicator
defines
the
end
of
the
field. A single field
may
extend beyond one
line
or
row;
such
a field is
called a continuedfield.
For
a continued field, a
start
field indicator is used
in
the
first
column
of
the
second
and
each
consecutivelineoccupied by
the
field.A stopfield
indicator
is
used
at
the
end
of
the
field.
If
a
start
field is
not
in
column 0 ofa linefollowing one
containing
a field
with
no stopfield,
the
end
of
that
line
is
the
implicit
end
offield. No explicit stop field is needed.
The
field
separator
or
block terminator,
as
selected on
the
Terminal
Configuration menu, is
transmitted
after·
the
contents of
the
field, as would occur normally.
FIELD
CHECKS.Two field
attributes,
the
««required"
attribute
and
the
««modified
data
tag",
are
checked
after
the.
key is pressed or
at
transmission time.
Other
attributes
are
checked
when
the
fields
are
being
filled by
the
user
or
when
the
field is to be exited.
Before
the.
keystroke
is acknowledged, a check is done to
ensure
that
all
««required" fields
have
data
entered
in
them. This check is done before
any
cursor repositioning
and
before
any
handshaking
is done. They
must
all be
in
this
state, even
though
none would be
transmitted,
given
the
current
mode conditions
and
cursor position.
The
<<<required"
field check is
not
done for
the
««send
display" (Ec
d)
data
transfer.
CLEARING
OF
TERMINATORS. Non-displaying
terminators
are
cleared
when
tabbed
over
or
when
a
<<<clear
display" operation is executed. They
are
not
cleared, however,
when
a
cursor-move keystroke
or
cursor-movement escape sequence is executed.
Block'terminators,
like
normal
characters,
are
not
cleared by
tabbing.
START
POINT.
When
in
Blockmode
with
the
Au t 0
Term<
J)
strap
set,
the
search
backwardfor
a block
terminator
or
non-displaying
terminator
includes
the
protected fields.
If
a
terminator
is
found
in
a protectedfield,
the
block
transfer
begins
at
the
start
of
the
next
unprotectedfield.
This is
not
a likely event, however.
Unlike
the
non-Format
mode case, a memory locked
area
is searched
(after
the
workspace is
adjusted completely)
and
is
treated
as
the
rest
of
the
workspa·ce is.
This
is
the
case also for
<<<home
up";
the
memory-locked
area
isonly special
in
Format
mode,
in
that
it
does
not
roll
up
or
down.
DATATRANSMITTED.
In
Format
mode, only
the
ASCII
characters
(both control codes
and
displayable characters)
in
unprotected fields
are
transmitted.
When
the
terminal
is
configuredto sendonly "modified" fields,
data
compression is performed.
~
When
in
Character, Block Line,
and
Block Page modes,
trailing
blanks
are
eliminated
from
the
field contents.
9-10
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