YSI 600LS - User Manual - Manual (Page 111)

Sondes Section 2
YSI Incorporated Environmental Monitoring Systems Operations Manual 2-105
6-( ) Multi SDI12. Modifies the SDI12 protocol as follows: (1) No SDI12 service request will be issued.
(2) Break commands will not cause a measurement reading to be aborted. Normally, you should leave this
feature “off”.
7-( ) Full SDI12. Enabling this feature forces full SDI-12 specification in order to pass the NR Systems
SDI-12 Verifier. Disabling this feature will allow the unit to be more fault tolerant and will save some
power. We recommend that you leave this feature “off”.
8-( ) Sample and Hold. This feature is designed to be activated ONLY for studies in which your sonde is
attached to a YSI 6500 Process Monitor. When “Sample and Hold” is active, the 6500 display and the
SCADA output of the 6500 becomes equivalent to the internal memory of the sonde while an Unattended
study is running. In the Unattended mode, the sonde “sleeps” between periodic samples with the interval
between samples defined by the user. This method of operation results the extension of both the sonde
battery life (not important in 6500 applications) and the time between required sensor maintenance
procedures (which is important to 6500 applications using Rapid Pulse DO). After activation of the feature
another entry will appear automatically which will allow you to input your sample interval which defines
how often data is transmitted to the 6500 display. This new sample interval will automatically become the
sample interval for the Run|Discrete sample mode of operation and you will not be able to change the
interval until Sample and Hold is deactivated. In addition, the interval in the Run|Unattended sample
mode will also change to the Sample and Hold interval. In this case, however, you will be able to change
the Unattended Sample interval, but with the caveat that the Sample and Hold interval will also change,
i.e., the Unattended sample interval and the Sample and Hold interval MUST be synchronized and the
software assures that this will be the case.
For DCP applications, when “Sample and Hold” is active, the routine which triggers optical wipers, the
sensor warm-up pattern, and the acquisition of data will be controlled by the sonde rather than the DCP. If
the Unattended mode of the sonde is inactive, the data will be stored in a memory buffer and then acquired
by the DCP when the “D” command is issued. If the Unattended mode is active, then the data will be
stored both in the memory buffer and sonde memory for acquisition by the DCP. Use of the “Sample and
Hold” feature with a DCP is particularly useful if you are also logging a back-up file to internal sonde
memory. In this case, the wiping and data acquisition sequence of the sonde will ONLY be triggered by
the sonde itself rather than by BOTH the sonde and the DCP and this will result in significantly less power
consumption from the DCP battery and/or power system.
NOTE CAREFULLY: When Sample and Hold is active, the sonde will behave as if it is in an
Unattended sample mode EVEN IF AN UNATTENDED SAMPLE HAS NOT BEEN ACTIVATED.
Therefore, to conserve batteries, you should always DEACTIVATE the Sample and Hold feature when
your sonde is not attached to the 6500 Process Monitor.
Select 3-Sensor to display and change user-configurable constants as shown in the following display. Type
the appropriate number to change to these parameters. Note that the listed items depend on which sensors
your have active in your sonde setup.