Campbell SDM-SIO4, Instruction Manual

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Section 3. Understanding How the SDM-SIO4 Handles Data
3-2
To enter a control character in the range of 0-255 decimal in a filter string,
formatter string or a user string you must use the ‘&hh’ format, where ‘&’
defines the following two characters, ‘hh’, to be a hexadecimal number between
00 and FF. For example, ‘&de’ would be character 222 decimal. To use ‘&’
within the string you must type ‘&&’ (i.e. && = & when in a string).
The hex. number must always be two ASCII characters.
Control characters can be entered for all commands in a similar way:
•
^M is carriage return, ^J line feed etc.
•
^^ means ^
•
"" means "
•
]] means ]
•
&& means &
•
&0d means line feed
•
&hex,hex used to enter 2-character hex. codes (0-9, A-F)
3.2 Input Filters
Input filters are used to convert received data into a form that is easy for the
datalogger to process. Filters are generally used to strip out the required values
from other, unnecessary, data transmitted from the sensor/device. The filters
will also convert the required data into a form that the datalogger can use.
For example, the sensor may output the (unusual) complex string ‘Sample data
+12.3, 23.567,0xAB,12.4’. From this string you may only require to record the
hexadecimal number 0xAB. A filter can be set up to strip out only this number,
and then convert it to a 4-byte floating point number which the datalogger can
use. The datalogger will then collect this value and place it into an input
location –in this case as 171 decimal.
You must
always
set up a filter if you want the datalogger to
collect data from the SDM-SIO4.
3.2.1 Filter Types
Simple Filters
These filters can be set up by the datalogger program, i.e. command line set-up
is not necessary. The four filters search for a specific data type to convert to
Campbell Scientific floating point format. The SDM-SIO4 continues searching
and reading data until it encounters a termination character (if this has been
specified in Instruction 113) The filters are as follows:-
•
Search for an ASCII floating point number to convert to Campbell
Scientific floating point format.*
NOTE
NOTE