Xylem 4046 ANALOG TO SDI-12 CONVERTER - Manual (Page 2)

2.1. Connections:
Analog inputs from the (2) external sensors are connected to ANA in1
and ANAin2 respectively with the common (ground reference) connection at
ANA Gnd. Take care to observe polarity and limit the voltage input to 5V dc.
The input ANAin1 corresponds to SDI parameter 0 (first) and its Slope and
Offset values correspond to “A”. Input ANAin2 corresponds to SDI parameter
1 (second) and its Slope and Offset values correspond to “B”. The EVNT In
corresponds to SDI Parameter 2 (third) and its Slope and Offset correspond
to “C”. Sensor Power (either 12VDC or 5.00VDC) is switched on before the
Analog measurement takes place. The sensor warm-up time is user
programmable. External power sources for the sensor other than the
switched power may cause problems with the Analog measurement if
they are energized before the internal switched power is activated.
3.0 SDI COMMANDS
All input and response characters are in ASCII format, 1200 baud, even
parity.
‘a’ denotes the sensor address.
Note: If second command is sent to the sensor after starting a measurement,
but before the measurement is ready, the sensor will abort the measurement.
Acknowledge Active: Returns a response acknowledging that the sensor unit is
active.
command a! sensor response a<CR><LF>
Send Identification:
Returns SDI version, company name, sensor model #, sensor version#.
command
aI! sensor response allccccccccmmmmmmvvv<CR><LF>
II= SDI version ccccccc=8 character vender ID mmmmmm=6 character model
ID vvv= 3 character sensor version
Address Query: Returns address for sensor. (Note Only one sensor may be on
the buss for this query)
command ?!
sensor response a<CR><LF>