User Manual
9
The
CS616()
CRBasic instruction has the following form.
CS616(
Dest, Reps, SEChan, Port, MeasPerPort, Mult, Offset
)
Dest
:
The
Dest
parameter is the variable or variable array in which to store
the results of the measurement.
Dest
must be dimensioned to at least the
number of
Reps
.
Reps
:
The
Reps
parameter is the number of measurements that should be
made using this instruction. If
Reps
is greater than 1,
Dest
must be an
array dimensioned to the size of
Reps
.
SEChan
:
The
SEChan
parameter is the number of single-ended channels
on which to make the first measurement. If the
Reps
parameter is greater
than 1, the additional measurements will be made on sequential channels.
Port
:
The
Port
parameter is the control port that will be used to enable the
CS616 sensor.
MeasPerPort
:
The
MeasPerPort
parameter is the number of control ports
to be used to control the CS616 sensor(s). If
Reps
is set to 4,
MeasPerPort
= 4 will result in the same port being used for all measurements.
MeasPerPort
= 1 will result in four sequential ports being used for the
measurements.
MeasPerPort
= 2 will result in one port being used for the
first two measurements, and the next port being used for the next two
measurements.
Mult, Offset
:
The
Mult
and
Offset
parameters are each a constant, variable,
array, or expression by which to scale the results of the measurement.
7.4.2
CS625 CRBasic Programming
The output of the CS625 is a square wave with amplitude of 0 to 3.3 Vdc
and a frequency that is dependent on the dielectric constant of the material
surrounding the probe rods. The CRBasic instruction
PeriodAvg()
is used
by the CR200(X) series dataloggers to measure the CS625 output period.
The period value is used in the calibration for water content. The period in
air is approximately 14.7 microseconds, and the period in saturated soil
with porosity 0.4 is approximately 31 microseconds.
The
PeriodAvg()
instruction has the following form.
PeriodAvg(
Dest, SEChan, Option, Cycles, Timeout, Port, Mult, Offset
)
Dest
:
The
Dest
parameter is a variable in which to store the results of the
measurement.
SEChan
:
The
SEChan
argument is the number of the single-ended channel
on which to make the measurement. Valid options are analogue channels 1
through 4. The green wire is connected to this channel number.
Option
:
The
Option
parameter specifies whether to output the frequency or
the period of the signal. Code 0 is typically used with the CS625 with a
multiplier (see below) of 1. Code 0 returns the period of the signal in
milliseconds.
Cycles
:
The
Cycles
parameter specifies the number of cycles to average
each scan.
Timeout
:
The
Timeout
parameter is the maximum time duration, in
milliseconds, that the datalogger will wait for the number of
Cycles
to be
