Xylem H-310 - Manual (Page 30)

C-4 Appendix C SDI-12 Command and Response Protocol
H-310
The Send Data command returns sensor data generated as the result of previous "aM!" or "aV!"
commands. Values returned will be sent in 33 characters or less. The sensor's data buffer will
not be altered by this command.
If the number of values returned by a "aD0!" command is less than the number specified by the
result of the previous "M" or "V" command, the rest of the data must be collected using "aD1",
"aD2!" .... and so on until all values specified have been collected.
If one or more values were specified and a "aD0!" returns no data, it means that the measurement
was aborted and a new "M" command must be sent.
The Following table is a listing of the responses to the Send Data command supported by the
W
ATER LOG ® H-310.
H-310 response to a "aD0!" command:
Note: "aD1!" - "aD9!" commands not supported (or needed)
Previous command Response format
"aM!" a+xxx.xxx+yy.y
"aM1!" a+xxx.xxx+yy.y+XXXXX+YYYYY
"aM2!" a+yy.y
"aM3!" a+xxx.xxx
"aM4!" a+zz.z
"aV!" a+123.456+78.9+p+q
Key Measurement Units
xxx.xxx Current Pressure Pounds-per-Square Inch (PSI).
yy.y Current Temperature Centigrade (C).
zz.z Input Voltage Volts (V)
XXXXX Current Pressure Raw reading
YYYYY Current Temperature Raw reading
p ROM checksum test 0 = Failed, 1 = Passed
q COP status 0 = Off, 1 = On
C.5 Send Acknowledge Command
Command Response
"a!" "a"
Where:
a Is the sensor address (0-9,*).
The Send Acknowledge command returns a simple status response which includes address of the
sensor. Any measurement data in the sensor's buffer is not disturbed.