Measurement Specialties
KPSI
®
Digital Series User’s Manual
Page 8
www.Meas-Spec.com
S e t t i n g t h e A d d r e s s
If you are using the sensor connected to common wiring with other SDI-12 sensors, you may
need to change the default sensor address. Otherwise, skip this section. A unique address
assigned to each sensor is an absolute requirement for multiple sensors to share the same
wiring. When the data recorder needs data from a particular sensor, it requests data using a
particular address. Only the sensor with the matching address can reply. Two or more sensors
with same address replying will garble this reply. The factory default SDI-12 address (0) is best
reserved only for single sensors operating alone on dedicated wiring.
using the get/set sensor address commands
No other SDI-12 sensors connected to the system should be set to address 0 or to the desired
sensor address. Hint: If you do not know the address of a particular sensor, first use the
Get
Unknown Address
command to have the sensor identify itself. Its syntax is as follows:
?!
NOTE:
There can be only one SDI-12 sensor connected to common wiring in
order for the
Get Unknown Address
command to work.
The SDI-12 command for changing a sensor’s address is
“A” (Set Sensor Address)
.
aAn!
Where
“a”
is the current address of the sensor,
“n”
is the new SDI-12 address
Valid addresses are 0 to 9, A to Z, a to z.
The sensor will issue a reply message in response to the command, if the command was
recognized. The message will be the new address “n.”
Note that both commands above follow the SDI-12 standard of ending with a “!”terminator.
As an example, the following Set Sensor Address command would set the sensor address from
0
to
5:
0A5!
The sensor will respond with the new address, which is “5.”
Subsequently, the address can be set to a different address, 9 for example, by the command:
5A9!
