Section 5. Programming the Datalogger
5-3
5.2.1 Understanding Parameter Options and Returned Values
In the following examples, ‘x’ indicates a single digit from 0 to 9.
When the command requires or returns values, each digit, or combination of
digits, can signify either a value, flag or setting.
Using Command 5 as an example:
Number of watch dog resets
| | Number of invalid commands executed
| | | Lithium battery level
| | | |
x x x x
The first value returned by Command 5 indicates:
Actual number of watch dog resets (two digits 00 to 99) – a value.
Number of invalid commands executed (single digit 0 to 9) – a value.
Level (state) of the lithium battery (0=low, 1=good) – a flag.
If the value returned was, for example, 1281, then it would have the following
meaning:
12 watch dog resets
8 invalid commands
1 battery level good
The second value returned shows whether or not data is available from a specific
port. A non-zero digit indicates that data is available, whereas a zero signifies that
no data is available.
Command 5 is explained in detail later.
When a command parameter requires values to be entered (e.g.
Command 1026), it is a good idea to always enter all four digits.
Only trailing zeros are significant to the SDM-SIO4, and so entering
0001 or 1 would be identical. However, if the first parameter needs
to be 1, you must enter 1000. The habit of always entering all four
values helps to minimise input errors.
5.2.2 Command 1: Poll of Available Data
This command has no additional options after the command. The SDM-SIO4
returns one Campbell Scientific floating point number to indicate if data is
available as below:
Port 4 data available
| Port 3 data available
| | Port 2 data available
| | | Port 1 data available
| | | |
x x x x
If any of these four digits is greater than zero then data is available.
Values per repetition = 1
NOTE
NOTE