In-Situ TROLL 9500 Operators Manual - Manual (Page 137)

132
TROLL 9500 Operator’s Manual 0095110 rev. 007 01/09
SECTION 19: SDI-12 OPERATION
s
0.0.
s
scribed in the tip above, only the parameters you select will be
reported.
s
reported.
REDUNDANT LOGGING (WIN-SITU 4 AND SDI-12)
If your MP TROLL 9500 supports internal logging, the instrument is
capable of running tests (programmed in Win-Situ) while participating
in an SDI-12 network; however Win-Situ cannot communicate with the
MP TROLL 9500 while it is trans mitting SDI-12 data, and conversely,
the instrument cannot receive or respond to SDI-12 commands while
connected to a PC serial port.
This “redundant logging” feature means
s
data can be retrieved using Win-Situ.
TROLL 9500 will continue to collect new data using its own internal
batteries and clock.
TIP: Depending on the SDI-12 data recorder used, rapid
sample schedules during a test may result in SDI-12
“retries.”
EXTENDED (ISCO) COMMANDS
Extended commands allow the data sampler to identify both the data
channels and channel units that correspond to the ASCII formatted
mOATING
The data sampler will first issue either a measure or a concurrent
measure command. These commands return the number of channels
that will be reported in a subsequent read command. This number
will correspond with the number of pairs returned by the extended
commands.
If the expected number of “Ix” pairs is not returned in response to the
“aXPR0!” command, additional “aXPRx!” commands will be issued
until all pairs are received.
REFERENCE
SDI-12, A Serial-Digital Interface Standard for Microprocessor-Based
Sensors, version 1.3. SDI-12 Support Group, Logan, Utah, April 7,
2000. Available at www.sdi-12.org.