SOMMER SPA-2, Руководство пользователя

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4
Number of measurement values
Request results
After each measurement, results are requested with the command
aDn!
, with
a
the sensor
address and
n
the index of the returned data string.
EXAMPLE
0D0!
Answer:
0+2591+706+25.53+0<CR><LF>
The leading
0
of the response is the sensor address.
Generally, the command
aD0!
is sufficient to request up to 9 measurement values. If more than 9
values need to be read, or if the values are returned in groups, the commands
aD1!
,
aD2!
,… may
need to be issued after
aD0!
. For example, if a measurement returns 8 values in two groups of 4,
the commands
aD0!
and
aD1!
need to be issued to receive all values.
Acquire continuous measurements
If the SDI-12 device is operating in continuous measurement mode (not polled by SDI-12), the com-
mand
aR0!
will request and return the current reading of the sensor. The values within the data
string follow the order listed in the measurement table. The first values in the response to the
aRn!
command is the sensor address.
EXAMPLE
0R0!
Answer:
0+2591+706+25.53+0<CR><LF>
If more than 9 values need to be read, or if the values are returned in groups,
the commands
aR1!
,
aR2!
,… may need to be issued after
aR0!
. For
example, if a measurement returns 8 values in two groups of 4, the com-
mands
aR0!
and
aR1!
need to be issued to receive all values.
Configure device
The configuration parameters of a SOMMER sensor are read with the command
aXRpp!
and writ-
ten with the command
aXWpp=vvv!
, with
a
the sensor address,
pp
the parameter identifier and
vvv
the value of the parameter.
Read and write a parameter
EXAMPLE
Reading of measurement interval (in this example menu item B)
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Manual 73