Table 8-2: SDI-12 addresses and positions
Numeric set Uppercase set
Lowercase set
W / 32
w / 58
X / 33
x / 59
Y / 34
y / 60
Z / 35
a / 61
{ – reset to factory address
8.1.2 Metadata
Every temperature point in a probe includes the following metadata, which can be retrieved
using the
aR1!
SDI-12 command. This information can be used to identify details of the
temperature probe and its individual temperature points.
Table 8-3: Metadata details
Name
Value range
Description
Serial
Number
0 to 65534
The serial number that is unique to each probe unit.
Location
Number
1 to 255
Each temperature sensor within a probe is assigned its own unique
location number which by default is in relation to the SDI-12 address
(see
Depth
Value
0 to 65535 cm
The
distance
values
in
centimet
re
s
(cm).
These
are
intended
to
reflect
the
profile
distances.
Typically,
the
top
most
temperature
point
would
be
designated
as
0
cm
and
if
the
next
temperature
point
below
was
10
cm
away,
then
its
distance
value
would
be
10
cm.
Users
may
designate
other
starting
values.
These
can
be
configured
at
the
time
of
ordering.
8.2
Long
cables
As
the
measurement
data
is
transferred
between
the
temperature
profiler
and
data
logger
digitally,
there
are
no
offset
errors
incurred
with
increasing
cable
length
as
seen
with
analog
ue
sensors.
However,
with
long
enough
cable
lengths,
the
digital
communications
will
break
down,
resulting
in
either
no
response
from
the
sensor
or
corrupted
readings.
The
original
SDI-12
standard
specifies
the
maximum
total
cable
length
for
the
cable
as
being
61 m
(200 ft),
but
we
are
able
to
exceed
this
limit
by:
CS225 Temperature String
14
