TDR SOIL MOISTURE MEASUREMENTS
4
FIGURE 3-3. Mounting 1502B in ENC TDR
TABLE 3-1. SDM Addresses
ADDRESS SDM1502
SDMX50
Base 4
Switches
Jumper Settings
1 2 3 4
MSD LSD
00
0 0 0 0
0
0
01
1 0 0 0
0
1
02
0 1 0 0
0
2
03
1 1 0 0
0
3
10
0 0 1 0
1
0
11
1 0 1 0
1
1
12
0 1 1 0
1
2
13
1 1 1 0
1
3
20
0 0 0 1
2
0
21
1 0 0 1
2
1
22
0 1 0 1
2
2
23
1 1 0 1
2
3
30
0 0 1 1
3
0
31
1 0 1 1
3
1
32
0 1 1 1
3
2
33
1 1 1 1
3
3
3.2 INSTALLING 1502B IN ENC TDR
The 1502B is mounted in the ENC TDR
enclosure by removing the handle (the required
Allen wrench is included with the ENC TDR)
and installing as shown in Figure 3-3.
3.3 DATALOGGER WIRING
3.3.1 SDM Wiring
Figure 3-4 shows the wiring of the SDM
communication cables from the SDM1502 and
SDMX50 to the datalogger. With the 21X, the
C1 connection from the SDM1502 must be
wired into analog input 1H with a 10 kilohm
resistor to C1. (This resistor is the short black
cable that is fastened to the SDM1502 handle
with a wire tie for shipping.) The resistor is not
used with the CR10.
The SDM1502 terminals are labeled above
the connector. The description for the
multiplexer terminals is on a label inside the
enclosure lid.
