Serial
Communications
PT12
Manual
7/20/2021
Page
39
of
48
5.2
PROTOCOL
5.2.1
COMMUNICATION
SEQUENCE
AND
TERMINATION
CHARACTERS
All
commands
sent
to
the
PT12
must
be
terminated
with
either
a
carriage
return
C
R
or
a
carriage
return
linefeed
combination
C
R
L
F
.
Both
C
R
and
C
R
L
F
terminators
are
identical
in
action
as
the
PT12
simply
ignores
the
L
F
character.
For
those
writing
communication
programs
to
communicate
with
the
PT12,
note
that
C
R
and
C
R
L
F
are
represented
by
the
following
values:
Symbol
Decimal
Hex
C
R
13
0D
C
R
L
F
13,10
0D 0A
When
using
a
terminal
emulator
such
as
Hyper
‐
terminal
or
Putty,
note
that
pressing
the
Enter
key
is
equivalent
to
sending
C
R
.
Regardless
of
the
command
sent,
the
PT12
will
reply
with
a
carriage
return
linefeed
C
R
L
F
terminator
at
the
end
of
the
response,
provided
the
command
was
recognized
as
valid.
Here
is
an
example:
T1?
C
R
L
F
(sent
by
the
computer
to
the
PT12)
-10.015
C
R
L
F
(sent
by
the
T1
back
to
the
computer)
T1?
C
R
(sent
by
the
computer
to
the
PT12)
-10.015
C
R
L
F
(sent
by
the
T1
back
to
the
computer)
I=1
C
R
(sent
by
the
computer
to
the
PT12)
C
R
L
F
(sent
by
the
T1
back
to
the
computer)
NOTE
:
Even
if
the
command
is
not
a
request
for
data,
but
rather
is
a
command
to
change
a
parameter,
the
PT12
still
responds
with
a
carriage
return
line
feed
combination
.
5.2.2
CASE
SENSITIVITY
All
commands
are
insensitive
to
case.
In
other
words,
it
does
not
matter
if
the
command
is
sent
in
upper
case
letters,
lower
case
letters,
or
as
some
combination
of
the
two.
For
example,
the
commands
T1?
and
t1?
appear
identical
to
the
PT12.
However,
with
two
commands
(
save=RHS
and
default=RHS
)
the
RHS
needs
to
be
capitalized.
This
is
to
prevent
an
accidental
overwrite
of
a
probe’s
configuration.
5.2.3
NUMERIC
VALUES
All
numeric
data
sent
to
or
received
from
the
PT12
is
done
so
in
either
standard
or
scientific
notation.
Sending
a
number
as
12.34
is
the
same
as
sending
it
as
1234e-2
or
as
1.234e1
.
Depending
on
the
value
of
numeric
responses
the
PT12
sends
out,
it
may
send
the
numbers
in
either
standard
or
scientific
notation.
Temperatures
and
resistances
will
be
sent
in
standard
notation,
but
some
coefficients
will
be
sent
in
scientific
notation
due
to
their
values.
Numeric
data
is
never
appended
with
text
of
any
kind.
In
other
words,
if
requesting
a
temperature
related
value,
only
the
numeric
portion
of
the
value
is
sent.
The
units
are
assumed
but
never
sent.
The
device
will
always
respond
in
°C
for
temperatures
and
Ω
for
resistances,
regardless
of
the
display
units
setting.
Some
values
simply
require
integer
numbers
such
as
1
and
0
for
On
and
Off,
while
others
might
expect
real
numbers
with
a
decimal
point.
The
PT12
recognizes
both
types
of
numbers
and
will
attempt
to
convert
the
values
received
to
the
correct
format
it
expects.
