Section 7. Installation
150
7.6.3.12 Execution and Task Priority
Execution of program instructions is divided among the following three tasks:
•
Measurement task — rigidly timed measurement of sensors connected
directly to the CR800
•
CDM task — rigidly timed measurement and control of
CDM/CPI
(p. 492)
peripheral devices
•
Digital task (a.k.a, SDM task) — rigidly timed measurement and control
of
SDM
(p. 513)
peripheral devices, pulse measurements, and RS-232
measurements.
•
Processing task — converts measurements to numbers represented by
engineering units, performs calculations, stores data, makes decisions to
actuate controls, and performs serial I/O communication.
Instructions or commands that are handled by each task are listed in table
Program Tasks
(p. 150).
These tasks are executed in either pipeline or sequential mode. When in pipeline
mode, tasks run more or less in parallel. When in sequential mode, tasks run
more or less in sequence. When a program is compiled, the CR800 evaluates the
program and automatically determines which mode to use. Using the
PipelineMode
or
SequentialMode
instruction at the beginning of the program
will force the program into one mode or the other. Mode information is included
in a message returned by the datalogger, which is displayed by the
datalogger
support software
(p. 86).
The
CRBasic Editor
pre-compiler returns a similar
message.
Note
A program can be forced to run in sequential or pipeline mode by
placing the
SequentialMode
or
PipelineMode
instruction in the
declarations section of the program.
Some tasks in a program may have higher priorities than others. Measurement
tasks generally take precedence over all others. Task priorities are different for
pipeline mode and sequential mode.
Summary of Contents for CR800 Series
Page 2: ......
Page 4: ......
Page 6: ......
Page 32: ......
Page 34: ......
Page 54: ......
Page 92: ......
Page 310: ......
Page 446: ...Section 8 Operation 446 8 11 2 Data Display FIGURE 100 CR1000KD Displaying Data ...
Page 448: ...Section 8 Operation 448 FIGURE 102 CR1000KD Real Time Custom ...
Page 449: ...Section 8 Operation 449 8 11 2 3 Final Storage Data FIGURE 103 CR1000KD Final Storage Data ...
Page 450: ...Section 8 Operation 450 8 11 3 Run Stop Program FIGURE 104 CR1000KD Run Stop Program ...
Page 452: ...Section 8 Operation 452 FIGURE 106 CR1000KD File Edit ...
Page 456: ......
Page 462: ......
Page 523: ...Section 11 Glossary 523 FIGURE 116 Relationships of Accuracy Precision and Resolution ...
Page 524: ......
Page 526: ......
Page 556: ......
Page 558: ......
Page 560: ......
Page 597: ......