Specifications

OPERATIONS
Page 92 MRC-565 Packet Data Radio Operations & Maintenance
The Sensor Definition Table is built in the form of a two dimensional matrix with rows and
columns. There is a row for each unique combination of sensor-address and SDI-12 command
type, and columns for selecting the SDI-12 command and expected number of measurements.
Data Collection
ID
Sensor Address
Data Set Name
SDI-12
Command
Number of
Values
1
0
Weather
M1
7
2
0
Rain
M2
3
3
1
Moisture
M
5
4
2
Snow Pillow
M
4
Figure 9. Example Sensor Table
Some sensors will output several measurements with one SDI-12 command. Others can, or will,
require several SDI-12 commands to collect all of the data measurements. The extended SDI-12
commands can be used to collect some particular measurements that are specific and pertain to
different features or capabilities of that sensor. The transparent mode will be used to control and
configure sensors.
When one sensor has several sets of data that require different SDI-12 commands to access, it
will be necessary to use the same sensor address in several rows of the table as in row 1-2 of the
example table. The row number becomes the collection ID for data collection and reporting
purposes. The columns of each row are configured parameters to define a sensor address, a data
set reference name, SDI command required and number of expected measurements.
The SDI, SEN, ID, ADDR, MTYPE,NVAL command creates the table rows.
The EVENT, GROUP, N, SDI[R:M], SDI[R:M], SDI[R:M]… command “maps” which data
values in the Sensor Table are to be combined into each SDATA group message. The number
‘N’ is the group number (1-16).
Each parameter following ‘N’ is a data value ID. There can be from 1 to 16 data values. The data
values can be pre-defined radio values (see radio HELP,EVENT command) or they can be SDI-
12 sensor measurements.
Using the pre-defined name of SDI[] in the command will specify a row [R] and measurement
number [M]. For example SDI[3:2] specifies row 3 and measurement 2. In this way, any
measurement can be reported in any group number and slot. There can be up to 16 groups with
16 values each for a total of 256 values per radio (or data collection site). The format of the
group SDATA reports are exactly the same as those created for data logger sites. Both data
logger reports and SDI sensor reports can be created for one site, but the total is limited to 16
groups and the data groups can not contain SDI measurements and Vice Versa.
As an example we could define two group SDATA reports from the Example Table:
EVENT,GROUP,1,SDI[1:1],SDI[1:2],SDI[1:3],SDI[1:4],SDI[1:5],SDI[1:6],SDI[1:7],
SDI[2:1],SDI[2:2],SDI[2:3]