Chapter 8
AutoCode Sim Cdelay Scheduler
8-10
ni.com
triggers arriving too quickly can prevent a task from ever posting any
output.
You must build an alternative AutoCode scheduler incorporating the new
pipeline stages presented above, and change the transition diagrams of
many of the task types to reflect changed output posting, enable, and
retriggering policies. In the case of the enable and retriggering policies,
however, you will want to include switches that let you fall back to the
original AutoCode behavior for these options because the Sim choices have
the previously mentioned drawbacks.
State Transition Diagrams of Tasks under Sim Cdelay
New transition diagrams were developed for free-running and enabled
periodic tasks, and for ATR triggered tasks. Figure 8-5 shows a new STD
for free-running periodic tasks. Figure 8-6 shows a new STD for ATR
triggered tasks. Figure 8-7 shows a new STD for ATR triggered tasks.
Figure 8-5.
New STD for Free-Running Periodic Tasks
IDLE
RUNNING
BLOCKED
Reset output
countdown timer
Timer has reached
zero, signal overflow
task
done
Countdown
timer is zero,
reset it and
post outputs
Timer greater
than zero,
decrement it