Campbell CR6 - Preventing Spectral Leakage; Sequential and Pipeline Processing Modes; Sequential Mode

6.6.2.4 Preventing spectral leakage
Matching the swept excitation to the expected resonant frequency range prevents spectral
leakage from complicating the spectral analysis. Vibrating wire sensors are usually optimized for
a single resonant frequency to overwhelm harmonic and sub-harmonic responses; so, spectral
leakage usually has little impact. Measurements of poorly constructed vibrating wire gages that
may have large harmonic and sub-harmonic responses are more susceptible to spectral leakage.
6.7 Sequential and pipeline processing
modes
The data logger has two processing modes: sequential mode and pipeline mode. In sequential
mode, data logger tasks run more or less in sequence. In pipeline mode, data logger tasks run
more or less in parallel. Mode information is included in a message returned by the data logger,
which is displayed by software when the program is sent and compiled, and it is found in the
Status Table, CompileResults field. The CRBasic Editor pre-compiler returns a similar message.
The default mode of operation is pipeline mode. However, when the data logger program is
compiled, the data logger analyzes the program instructions and automatically determines which
mode to use. The data logger can be forced to run in either mode by placing the
PipeLineMode or SequentialMode instruction at the beginning of the program (before
the BeginProg instruction).
For additional information, visit the Campbell Scientific blog article, "Understanding CRBasic
Program Compile Modes: Sequential and Pipeline."
6.7.1 Sequential mode
Sequential mode executes instructions in the sequence in which they are written in the program.
After a measurement is made, the result is converted to a value determined by processing
arguments that are included in the measurement instruction, and then program execution
proceeds to the next instruction. This line-by-line execution allows writing conditional
measurements into the program.
NOTE:
The exact time at which measurements are made in sequential mode may vary if other
measurements or processing are made conditionally, if there is heavy communications
activity, or if other interrupts occur (such as accessing a Campbell Scientific memory card).
6. Measurements 88