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Figure 41 - Serial talk through to communicate directly with serial sensors.
o
SDI12
. Similar to serial talk-through but customised for
SDI12 communications. The screenshot below shows a
sample SDI12 session to confirm that an instrument is
operating correctly.
Figure 42
–
SDI12 interactive session confirming correct sensor operation.
Type
{enter}
several times
A CR300> command prompt is returned
Type
SDI12{enter}
The Ai1 asks which port to use C1 or C2. C1 is normally used for
SDi12
Type
1{enter}
for C1
The Ai1 enters SDI12 terminal mode
Type
?!{enter}
The ? asks for any sensors connected to the bus to respond. The !
must be at the end of all SDI12 commands to transmit the request.
This only works if a single sensor is connected, otherwise all sensors
may respond resulting in garbage. If multiple sensors are
connected, disconnect some or advance to the next step
Type
0I!
Assuming sensor address 0 responds, this asks for the sensor
Identification
. If a different address is used, substitute for this
number in all subsequent commands. In this example, the
instrument 013YSIIWQSGEXOSND100 responds, a YSI EXO sonde.
The exact format of this response is manufacturer specific
Type
0M!
This initiates a measurement. The response is of the format atttn
where a is the address, ttt is the time in seconds for the
measurement to be ready and n are the number of data points. In
this example the instrument responds with 00179 meaning
instrument address 0 will have 9 parameters ready in 017s.
Wait at least ttt seconds
and type
0D0!
Requests the first block of data. The response is of the format
a+n.nnn+m.mmm+… where a is the address and n.nnn and m.mmm
are measurements. If there are more measurements to return,
request 0D1! and 0D2! for subsequent blocks of data until complete
SDI12 terminal mode can operate in parallel to datalogger issued
SDI12 commands however SDI12 Failed or SDI12 Busy may be
returned if the datalogger is performing another program operation.
o
For advanced connections (such as FTP or email SMTP) it is possible to send filtered IP Trace
information to a serial port, or to save these to a public variable. Refer to CRBasic help on
IPTrace
instruction for further details.
o
For a full list of the available terminal commands, use both
HELP
and
H
for a list.
