HP 54501A - Page 46

Command
Error.
A
command
error
will
be
reported
if
the
instrument
detects
a
syntax
error
or
an unrecognized
command
header.
Execution
Error.
An
execution
error
will
be
reported
if
a
parameter
is
found
to
be
out of
range,
or
if
the
current
settings
do
not allow
execution
of
a requested
command
or
query.
Device-specific
Error.
A
device-specific
error
will
be
reported
if
the
instrument
is
unable
to
execute
a
command
for
a
strictly
device
dependent
reason.
Query
Error.
A
query
error
will
be
reported if
the
proper
protocol
for
reading
a
query
is
not
followed.
This
includes
the
interrupted
and
unterminated
conditions
described
below.
Unterminated
Condition.
If
the
controller
attempts
to
read
a
<
response
message
>
before
terminating
the
<
program
message
>,
a
query
error
will
be
generated.
The
parser
will
reset
itself,
and
the
response
will
be
cleared from
the
output
queue
of
the
instrument
without
being
sent
over
the
bus.
Interrupted Condition.
If
the
controller
does
not read
the
entire
<
response message
>
generated
by a
query
message
and
then
attempts
to
send
another
<
program
message
>,
the
device
will
generate
a
query
error.
The
unread
portion
of
the
response
will
then
be
discarded
by
the
instrument.
The
interrupting
<
program
message
>
will
not
be
affected.
Buffer
Deadlock.
The
instrument
may
become
deadlocked
if
the
input
buffer
and
output
queue
both
become
full.
This
condition
can
occur
if
a
very
long
<
program
message
> is
sent
containing
queries
that
generate
a
great
deal
of
response
data.
The
instrument cannot accept any
more
bytes,
and
the
controller
cannot
read
any
of the
response
data until
it
has
completed
sending
the
entire
<
program
message
>.
Under
this
condition
the
instrument
will
break
the deadlock
by
clearing
the
output
queue,
and
continuing
to
discard
responses
until
it
comes
to
the
end
of
the
current
<
program
message
>.
The
query
error
bit
will
also
be
set.
Message
Communication and
System
Functions
HP
54501A
3-4
Programming