Campbell CR6 Series, Operator'S Manual

Page: 312 / 690

Section 7. Installation
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where:
0 is the SDI-12 address.
13 is the SDI-12 version (1.3).
NRSYSINC indicates the manufacturer.
100000 indicates the sensor model.
1.2
is the sensor version.
101
is the sensor serial number.
SDI-12 Start Measurement Commands
Measurement commands elicite responses in the form:
atttnn
where:
a is the sensor address
ttt is the time (s) until measurement data are available
nn
is the number of values to be returned when one or more subsequent
D!
commands are issued.
aMv!
Starts a standard measurement. Qualifier v is a variable between 1 and 9. If
supported by the sensor manufacturer,
v
requests variant data. Variants may
include alternate units (e.g., °C or °F), additional values (e.g., level and
temperature), or a diagnostic of the sensor internal battery.
Syntax:
aMv!
As an example, the response from the command 5M! is:
500410
where:
5 reports the sensor SDI-12 address.
004 indicates the data will be available in 4 seconds.
10
indicates that 10 values will be available.
The command 5M7! elicites a similar response, but the appendage 7 instructs the
sensor to return the voltage of the internal battery.
aC!
Start concurrent measurement. The CR6 requests a measurement, continues
program execution, and picks up the requested data on the next pass through the
program. A measurement request is then sent again so data are ready on the next