Section 3. Understanding How the SDM-SIO4 Handles Data
3-5
2.
n8 discards everything up to 12.65V.
3.
F converts the number to Campbell Scientific floating point. If a valid number
is not found -99999 is sent to the datalogger.
4.
i[c] waits for the trigger character ‘c’ of ‘current’.
5.
n8 discards everything up to 12mA.
6.
F converts the number to Campbell Scientific floating point. If a number is not
found -99999 is sent to the datalogger.
This filter will repeat the above operations on all incoming values.
Predefined Filter Strings
A small number of fixed filter strings are pre-defined as follows:
Filter No.
Filter String Used
256
r1
257
r2
258
r3
259
r4
3.3 Output Formatting
The output formatters are used to format data from the datalogger into English
text messages, send strings/commands to sensors and to output text to a display.
For example, you may have a display on which you want to show air temperature
and humidity. The datalogger would take the measurements from the sensors, and
place two values into appropriate input locations. It would be impractical for the
datalogger to store text labels in this way, and so you could use the SDM-SIO4 to
send a label to the display along with the data from the datalogger.
The final result may be displayed as:
The temperature is 23.7C
The humidity is 65.8%
The string generated would then be transmitted from the selected serial port.
Because the formatter is programmable, almost any string can be output from the
serial port, either by programming the datalogger or by using the command line.
3.3.1 Simple Output Formatter
This can be set up by the datalogger and allows data to be transmitted out of the
SDM-SIO4 in a number of simple formats. It is not necessary to use the command
line mode to use these formats. Simple output formats are as follows:
•
Convert a location sent into ASCII floating point. If this option is selected an
extra ASCII character/delimiter can be added to the end of the ASCII number
sent.
•
Convert a location sent into an ASCII hex pair. If this option is selected an
extra ASCII character/delimiter can be added to the end of the hex number
sent.
•
Convert a location sent into an 8-bit binary byte. If this option is selected an
extra ASCII character/delimiter can be added to the end of the byte sent.
