Campbell Wintersense SDI-12, Руководство по эксплуатации продукта

Страница: 15 / 44

data logger program exclusively with Short Cut . If your data acquisition needs are more complex,
the files that Short Cut creates are a great source for programming code to start a new program
or add to an existing custom program.
NOTE:
Short Cut cannot edit programs after they are imported and edited in CRBasic Editor .
A Short Cut tutorial is available in QuickStart (p. 2). If you wish to import Short Cut code into
CRBasic Editor to create or add to a customized program, follow the procedure in Importing
Short Cut code into CRBasic Editor (p. 27).
Programming basics for CRBasic data loggers are provided in the following section.
7.2.1 CRBasic programming
A downloadable example program is available at
https://www.campbellsci.
eu
/downloads/wintersense-sdi12-example-program .
The SDI12Recorder() instruction sends a request to the sensor to make a measurement and
then retrieves the measurement from the sensor. See SDI-12 measurements (p. 9) for more
information.
For most data loggers, the SDI12Recorder() instruction has the following syntax:
SDI12Recorder (Destination, SDIPort, SDIAddress, “SDICommand”, Multiplier, Offset,
FillNAN, WaitonTimeout)
Valid values for the
SDIAddress
are 0 through 9, A through Z, and a through z; alphabetical
characters need to be enclosed in quotes (for example,
“A”
). Also enclose the
SDICommand
in
quotes as shown. The Destination parameter must be an array. The required number of
values in the array depends on the command (see Table 7-2 [p. 10]).
FillNAN
and
WaitonTimeout
are optional parameters (refer to CRBasic Help for more
information).
7.2.2 SDI-12 measurements
The Wintersense SDI-12 responds to the SDI-12 measurement commands shown in Table 7-2 (p.
10). When the data logger issues an M! command, the sensor should respond immediately
indicating how long it will take to perform the measurement. The data logger then waits that
amount of time or if the sensor finishes sooner, it will send a service request to the data logger
indicating data can be collected. After receiving the service request or waiting the indicated time,
the data logger will send the
D! command to collect the data.
The
C!
command follows the same pattern as an
M!
command with the exception that it does
not require the data logger to pause its operation until the values are ready. Rather, the data
Wintersense SDI-12 9