Campbell Scientific CR1000 Measurement and Control System User Manual

Page 175

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Section 7. Installation

175

 

Table 25. Standard SDI-12 Command and Response Set

Command Name

Command Syntax

1

Response

2

Start Concurrent Measurement

aC!

atttnn<CR><LF>

Additional Concurrent
Measurements

aC1!

.
.
.

aC9!

atttnn<CR><LF>
atttnn<CR><LF>
atttnn<CR><LF>
atttnn<CR><LF>
atttnn<CR><LF>

Additional Concurrent
Measurements and Request CRC

aCC1! ... aCC9!

atttnn<CR><LF>

Continuous Measurements

aR0! ... aR9!

a<values><CR><LF> (formatted like the D commands)

Continuous Measurements and
Request CRC

aRC0! ... aRC9!

a<values><CRC><CR><LF> (formatted like the D
commands)

1

If the terminator '!' is not present, the command will not be issued. The CRBasic SDI12Recorder() instruction, however, will still pick up data

resulting from a previously issued C! command.

2

Complete response string can be obtained when using the SDI12Recorder() instruction by declaring the

Destination

variable as String.

3

This command may result in a service request.

 

Address Commands

A single probe should be connected to an SDI-12 input when using these
commands.

Address Query Command (?!)

Command ?! requests the address of the connected sensor. The sensor replies to
the query with the address, a.

Change Address Command (aAb!)

Sensor address is changed with command aAb!, where a is the current address
and b is the new address. For example, to change an address from 0 to 2, the
command is 0A2! The sensor responds with the new address b, or in this
example, 2.

Send Identification Command (aI!)

Sensor identifiers are requested by issuing command aI!. The reply is defined by
the sensor manufacturer, but usually includes the sensor address, SDI-12 version,
manufacturer's name, and sensor model information. Serial number or other
sensor specific information may also be included.

An example of a response from the aI! command is:

013NRSYSINC1000001.2101 <CR><LF>

where:

Address = 0

SDI-12 version =1.3

Manufacturer = NRSYSINC

Sensor model = 100000

Sensor version = 1.2

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