System philosophy
HARDWARE REFERENCE MANUAL
34
Revision 5.0
2.6
Program control and multi-tasking using
BASIC programs only
The Trajexia system has programs, processes and multi tasking control.
2.6.1
Program control
The Trajexia system can control 22 processes that are written as BASIC
programs. When the program is set to run, the program is executed.
Processes 0 to 19 are low priority, 20 and 21 are high priority.
2.6.2
Processes
The "Terminal Window" of Trajexia Studio has its own process (process 22).
This terminal window is used to write direct BASIC commands to the
TJ2-MC__ independent to other programs. These commands are executed
after you press the Enter button.
2.6.3
Multi-tasking
fig. 24
Each cycle time is divided into 4 time slots. User processes run in 3 slots
according to the priority and type of the process. The rules which type of
process is run in which slot are defined in the table below.
Slot 1
Slot 2
Slot 3
Cycle time
Slot 4
CPU slot
Operation
CPU slot 1
Execute whichever comes first in the list:
•
Low priority BASIC Program, or
•
High priority BASIC Program, or
•
PLC
CPU slot 2
Execute whichever comes first in the list:
•
PLC, or
•
High priority BASIC Program, or
•
Low priority BASIC Program
CPU slot 3
System processes