Control Techniques Epsilon EP-P Reference Manual page 132

The following two figures are timing diagrams of a cyclic program with different utilization values (showing the effect) and a user program
initiated to run on several tasks.
Figure 130:
Figure 131:
The two figures show how the Real Time program is executed prior to the user program and how the size of the Real Time program effects the
time left in the update rate for the user program to complete.
Figure 132:
118
Cyclic Program Utilization
set to 70%
Control Loop
Cyclic Program
T0
User Program
Update Rate
Cyclic Update = 3x Update Rate
Diagram of User Programs on Two Tasks and a Cyclic Program
Cyclic Program Utilization
set to 70%
Control Loop
Cyclic Program
T0
User Program
Update Rate
Cyclic Update = 3x Update Rate
Diagram of User Programs on Three Tasks and a Cyclic Program
Control Loop
Real Time Program
T0
User Program
Update Rate
Diagram of User Program and a Real Time Program
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Control Loop + Cyclic Prog + User Progs on two Tasks. Cyclic
Program Utilization set to 70% means cyclic program is suspended
after 70% of update is reached, then resumed next update
T1 T0 T1
Control Loop + Cyclic Prog + User Progs on three Tasks. Note how
when the number of Tasks is the same as the Cyclic Program
Update Rate setting, some programs get shortchanged. This
should be avoided by changing the Cyclic Program Update Rate
T1 T2 T0
Control Loop + Real Time Prog + User Prog on one Task
T0 T0 T0
T0 T1
T1 T2
T0 T0
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