Campbell Scientific CR800 and CR850 Measurement and Control Systems - Manual (Page 185)

Section 7. Installation
185
CRBasic Example 35. Using an SDI‐12 Extended Command
'SDI-12 extended command "XT23.61!" sent to CH200 Charging Regulator
'Correct response is "0OK", if zero (0) is the SDI-12 address.
'
'Declare Variables
Public SDI12command As String
Public SDI12result As String
'Main Program
BeginProg
Scan (20,Sec,3,0)
SDI12command = "XT" & FormatFloat(PTemp,"%4.2f") & "!"
SDI12Recorder (SDI12result,1,0,SDI12command,1.0,0)
NextScan
EndProg
7.8.3.2.2 SDI-12 Sensor Mode
The SDI12SensorSetup() / SDI12SensorResponse() instruction pair programs
the CR800 to behave as an SDI-12 sensor. A common use of this feature is the
transfer of data from the CR800 to other Campbell Scientific dataloggers over a
single-wire interface (SDI-12 port to SDI-12 port), or to transfer data to a third-
party SDI-12 recorder.
Details of using the SDI12SensorSetup() / SDI12SensorResponse() instruction
pair can be found in the CRBasic Editor Help. Other helpful tips include:
Concerning the Reps parameter in the SDI12SensorSetup(), valid Reps when
expecting an aMx! command range from 0 to 9. Valid Reps when expecting an
aCx! command are 0 to 20. The Reps parameter is not range-checked for valid
entries at compile time. When the SDI-12 recorder receives the sensor response
of atttn to a aMx! command, or atttnn to a aCx! command, only the first digit n,
or the first two digits nn, are used. For example, if
Reps is mis-programmed as
123, the SDI-12 recorder will accept only a response of n = 1 when issuing an
aMx! command, or a response of nn = 12 when issuing an aCx! command.
• When programmed as an SDI-12 sensor, the CR800 will respond to a variety
of SDI-12 commands including aMx! and aCx!. The following rules apply:
1. A CR800 can be assigned only one SDI-12 address per SDI-12 port. For
example, a CR800 will not respond to both 0M! AND 1M! on SDI-12 port
C1. However, different SDI-12 ports can have unique SDI-12 addresses. Use
a separate SlowSequence for each SDI-12 port configured as a sensor.
2. The CR800 will handle Additional Measurements (aMx!) commands. When
an SDI-12 recorder issues aMx! commands as shown in CRBasic example
SDI-12 Sensor Setup
(p. 186),
measurement results are returned as listed in table
CRBasic example SDI-12 Sensor Setup -- Results
(p. 186).