Campbell Scientific AM16/32A Multiplexer - Manual (Page 30)

AM16/32A Relay Analog Multiplexer
6.3 Half Bridge
his type may be subdivided into three categories
based on completion resistance and the presence or absence of
s completion resistor(s) are
panel (example: a CSI 107 probe modified
n,
d
ay
6.3.1 Half Bridge M
Datalogger
Sensor to Multiplexer wiring - up to three half bridges may be
he
ger
(Figure 12).
exer
t
log
ls to analog ground in CR10(X) or to “
Measurements
Measurements of t
measured excitation. If the sensor'
installed at the datalogger
for multiplexer use), then three probes per SET may be excited and
measured in “4x16” mode (Figure 12). However, if the circuit is
completed within the sensor (e.g. potentiometers), then excitatio
wiper signal, and ground must be multiplexed. Because excitation
and ground may be multiplexed in common, up to two sensors per
SET may be measured (Figure 13). If measured excitation is require
(i.e. four wire half-bridge), then only one sensor per SET of four m
be measured (Figure 14).
easurement with Completion Resistor at
connected to one input SET in “4x16” mode, provided that t
sensors’ three completion resistors are located at the datalog
Multiplexer to Datalogger wiring - Signal lines from the multipl
COM terminals tie to three consecutive single-ended analog inpu
channels. Three precision completion resistors connect from ana
input channe
” in the other
dataloggers.
/
0
"4 X 16" Mode
COM H (ODD)
COM L
COM H (EVEN)
COM L
ODD H
ODD L
EVEN H
EVEN L
SHIELD SENSOR SHIELDS COM
MUXSIGNAL
SHIELD
CR23X/
CR800/
CR850/
CR1000
21X/
CR7 CR10(X)
CR3000/
CR5000
EX E E VX
H H H H
L L L L
H H H H
AG
G
FIGURE 12. Half Bridge (Modified 107 Temperature Probe) Hook-up and Measurement.
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