D.1.3 Start verification command (aV!)
The response to a Start Verification command can include hardware diagnostics, but like the
aI!
command, the response is not standardized.
Command:
aV!
Response:
atttn<CR><LF>
a
= sensor address
ttt
= time, in seconds, until verification information is available
n
= the number of values to be returned when one or more subsequent
D!
commands are
issued
D.1.4 Address query command (?!)
Command
?!
requests the address of the connected sensor. The sensor replies to the query with
the address,
a
. This command should only be used with one sensor on the SDI-12 bus at a time.
D.1.5 Change address command (aAb!)
Multiple SDI-12 sensors can connect to a single SDI-12 terminal on a data logger. Each device on
a single terminal must have a unique address.
A 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
, which in this case is 2.
NOTE:
Only one sensor should be connected to a particular terminal at a time when changing
addresses.
D.1.6 Start measurement commands (aM!)
A measurement is initiated with the
M!
command. The response to each command has the form
atttn<CR><LF>
, where
a
= sensor address
ttt
= time, in seconds, until measurement data is available. When the data is ready, the sensor
notifies the data logger, and the data logger begins issuing
D
commands.
n
= the number of values returned when one or more subsequent
D
commands are issued. For
the
aM!
command, n is an integer from 0 to 9.
CS650 and CS655 Water Content Reflectometers
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