Xylem SDI-12 RADAR - Manual (Page 28)

SDi-12 CommaND & reSPoNSe
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This command is similar to the “am1!” command, however, the nn field has an extra digit and the
sensor does not issue a service request when it has completed the measurement. Data values
generated in response to this command are stored in the sensor’s buffer for subsequent collection
using “D” commands. The data will be retained in the sensor until another “m”, “C”, or “V”
command is executed.
Command response Description
“aC1!” “atttnn” initiate measurement
where:
a is the sensor address (“0-9”, “a-Z”, “a-z”, “*”, “?”).
C is an upper-case aSCii character
ttt is a three digit integer (000-999) specifying the maximum time, in seconds, the sensor
will take to complete the command and have measurement data available in its buffer.
nn is a two digit integer (00-99) specifying the number of values that will be placed in the
data buffer. if “n” is zero (0), no data will be available using subsequent “D” commands.
The data recorder may wake the sensor with a break and collect the data anytime after the specified
processing time has elapsed. This command may not work for some applications, as the data logger
must wait 1 second before collecting data, which may not work for applications requiring a faster
response.
Concurrent “aC1!” Command
This command is similar to the “am2!” command, however, the nn field has an extra digit and the
sensor does not issue a service request when it has completed the measurement. Data values
generated in response to this command are stored in the sensor’s buffer for subsequent collection
using “D” commands. The data will be retained in the sensor until another “m”, “C”, or “V” command
is executed..
Command response Description
“aC2!” “atttnn” initiate measurement
where:
a is the sensor address (“0-9”, “a-Z”, “a-z”, “*”, “?”).
C is an upper-case aSCii character
ttt is a three digit integer (000-999) specifying the maximum time, in seconds, the sensor
will take to complete the command and have measurement data available in its buffer.
nn is a two digit integer (00-99) specifying the number of values that will be placed in the
data buffer. if “n” is zero (0), no data will be available using subsequent “D” commands.
Concurrent “aC2!” Command