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2 sdi-12 sensor mode – Campbell Scientific CR1000 Measurement and Control System User Manual

Page 184

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Section 7. Installation

184 

 

 

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 CR1000 to behave as an SDI-12 sensor. A common use of this feature is the
transfer of data from the CR1000 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 CR1000 will respond to a

variety of SDI-12 commands including aMx! and aCx!. The following rules
apply:

1. A CR1000 can be assigned only one SDI-12 address per SDI-12 port. For

example, a CR1000 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 CR1000 will handle Additional Measurements (aMx!) commands. When

an SDI-12 recorder issues aMx! commands as shown in CRBasic example
SDI-12 Sensor Setup

(p. 185),

measurement results are returned as listed in table

CRBasic example SDI-12 Sensor Setup -- Results

(p. 185).