Xylem H-340SDI - Manual (Page 10)

1-4 H-340SDI Introduction
H-340SDI
1.5 Installation
Install the H-340SDI in an open location where it will not be in the rain shadow of trees or
buildings. A rooftop location helps prevent vandalism and the accumulation of leaves and
debris. Bolt or screw the 3-mounting feet to the structure to prevent upset in high winds. Adjust
the three self-leveling screws until the “bulls eye” level is centered.
1.6 Programming Your Data Recorder
You must prepare your data recorder to receive and record the H-340SDI data. Since data
recorders differ widely, refer to your recorder manufacturer's directions. In general, program the
data recorder to input five values via the SDI-12 port. Usually only one or two of the parameters
is actually recorded. Your data recorder must issue an “aM!” command then collect the data with
a “aD0" command, as explained in Chapter 2. The H-340SDI places five data values in its data
buffer:
+AA.AAA+BBB+CC.CCC+DD.DDD+EE.EEE
Where:
+AA.AAA = Rainfall accumulation since last measurement (inches of rain)
+BB = Number of raw bucket tips since last measurement (counts)
+CC.CCC = Total rainfall accumulation since reset. (inches of rain)
+DD.DDD = Total rainfall accumulation today (inches of rain)
+EE.EEE = Total rainfall accumulation yesterday (inches of rain)
All five of these parameters are automatically reset at power-up, or manually with the extended
SDI-12 “aXRA” Reset Accumulators command.
1.7 Programming the H-340SDI
The H-340SDI comes from the factory with the following settings:
SDI Address: 0
Slope: 1.0
Daily Reset Time: 00:00:00
Time of day: 00:00:00
With these values the data will be in units of inches of rainfall. The setup is stored in EEPROM
within the H-340SDI and will not be lost if the power is disconnected. The extended commands
for changing the slope and sensor address are described in detail in Chapter 2. If more than one
sensor is to be connected to the SDI-12 bus, make certain each sensor has a unique sensor
address.