Campbell Scientific AM16/32A Multiplexer - Manual (Page 28)

AM16/32A Relay Analog Multiplexer
I=1 ‘set sub scan loop counter
SubScan (0,mSec,16)
‘Clock Mux PulsePort (5,10000)
CS616 (Period(I),3,1,6,3,1.0,0) ‘measure 3ea CS616 probes
I=I+3
NextSubScan
‘
For I=1 to 48 ‘convert CS616 period to Volumetric Water Content
VWC(I)=a0 + a1*Per 2*Period(I)^2 iod(I) + a
Next
‘
PortSet (4,0) ‘Set Mux Reset line Low
flag(1)= low
‘+++++++++++++++++++++++++++ EndIf
‘
able Dat30m ‘Call Output Tables CallT in
NextScan
EndProg
5.4 General Programming Considerations
elay time associated
es
r
t their
The excitation voltage, integration time, and d
with measuring the signal, and the speed at which the channels are
advanced can be varied within the datalogger program. In general,
longer delay times are necessary when sensors and datalogger are
separated by longer lead lengths. Consult your datalogger manual for
additional information on these topics.
6. Sensor Hook-up and Measurement Examples
This section covers sensor-to-AM16/32A connections as well as
AM16/32A-to-datalogger connections. The following are exampl
only, and should not be construed as the only way to make a
particular measurement. See the Measurement Section of you
datalogger manual for more information on basic bridge
measurements. Most of the following examples do not depict
datalogger-to-AM16/32A control connections (Section 4.1), bu
presence is implied and required. Campbell Scientific recommends
that only sensor shield (drain) wires be connected to AM16/32A
shield terminals labeled (“
”).
6.1 Single-Ended Analog Measurement without Sensor
o AM16/32A wiring - one single-ended sensor not requiring
e COM signal line is input to a
Excitation
Sensor t
excitation can be connected to an input SET with panel mode switch
set to “2x32”.
Multiplexer to Datalogger wiring - Th
single-ended analog input channel. The COM signal-ground line is
tied to “
” at the CR23X, 21X, or CR7, and to “AG” at the
CR10(X). Up to 32 single-ended sensors can be measured by one
single-ended datalogger channel in this manner.
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