YSI 9600 - Manual (Page 50)

remote transmission. NOTE CAREFULLY: The ONLY data returned by the 9600 to the DCP will be the
Nitrate-N concentration in units of mg/L.
It is important to note, however, that the 9600 operates in a slightly different manner from YSI 6-series
sondes in the SDI-12 mode as described below. The important difference to the average user is the method
of set-up before attachment of the sonde or 9600 to the DCP.
• For a multiparameter YSI 6-series sonde, the user attaches the instrument to a computer prior to
deployment and makes sure that the desired sensor and report output are present and that other factors
such as the number of wiping operations for the optical sensors and the warm-up time for the oxygen
sensor are correct. The instrument is then attached to the DCP that has been programmed via its own
software to control the data acquisition from the sonde. The first key is that it is NOT necessary to
start a logging study in the sonde software prior to attachment to the DCP. The second key is that the
timing of data acquisition by the instrument is controlled by the DCP.
• For the 9600, the user attaches the nitrate monitor to a computer prior to deployment and goes through
the standard 9600 set-up procedure as for a study that does not involve use of a DCP. In addition, the
user MUST ACTUALLY START A DEPLOYMENT with the 9600 during the predeployment
interface with NUview software. The instrument is then taken to the field and attached to the DCP
which, as for 6-series sondes, has been programmed to control the data acquisition from the 9600.
The first key is that the 9600 MUST already be running a study prior to attachment of the DCP. The
second key is that the DCP will NOT control the timing of the analytical sequence; instead only the
acquisition of data from the 9600 is controlled by the DCP. Because the SDI-12 interface protocol is
carried out in this manner, the data sent to DCP after it issues a request will be the last data point
logged to 9600 memory. The date/time stamp on the data that originates in the DCP thus could be in
error by as much as the Sample Interval of the 9600. For example, if the 9600 is logging data
internally at a 1 hour sample with the analytical sequence starting on the hour, the data from this
sequence will not be logged to 9600 memory until approximately 15 minutes after the hour. If the
DCP, requests data from the 9600 at 10:00, then the last available data in memory will have been
logged at 9:00 and it will be this data which will be transferred to the DCP. The DCP date/time stamp
will thus be 10:00 for data which was acquired at 9:00 and this small error will have to be accounted
for in data analysis. For this reason, the 9600 will upload the last sample time to the DCP, as well as
the nitrate readings. NOTE: No Date/Time Stamp from the 9600 will be transferred to the DCP, only
nitrate concentration values.
NOTE CAREFULLY: When using your 9600 with a data collection platform (DCP) via an SDI-12
interface, the MINIMUM SAMPLE INTERVAL ALLOWED IS 30 MINUTES.
5.5.2 USING THE 9600 WITH THE YSI 6200
The YSI 6200 Data Collection Platform can be purchased from Endeco/YSI along with the supporting
software for the DCP that is designated EcoWatch DCP. Key advantages of the 6200 for use with the
9600 are (1) the physical interface is simple in that the MS-8 connector from a 96XX cable can be directly
attached to its mating connector on the DCP and (2) the setting up of the software interface is more facile
than for most generic DCPs due to the use of EcoWatch DCP. If you would like more information on the
YSI 6200 or need additional support for setting up your existing 6200 with a 9600 Nitrate Monitor, please
use the following contact information:
Endeco/YSI
13 Atlantis Drive
Marion, MA 02738
800-363-3269
YSI Environmental 50 Model 9600 Nitrate Monitor