[plexil-support] Lookup(time,tol) always returns zero?

[Chris L. <Chr...@md...>]

Good morning,

I am a complete newcomer to PLEXIL, so please excuse me if this is problem is due solely to my ignorance.

It appears that Lookup(time, tolerance) always returns 0.
I am using plexil-3 on Ubuntu 12.04.
The test program is a modification of plexil-3/examples/temporal/TimedIterationTest.ple
[Note that similar results were found using plexil 2.5 both precompiled and rebuilt, using timed-iteration.ple]


Code snippet below:
TimedIterationTest:
{

  // variables snipped here

  foo = TimedIterationTest.EXECUTING.START;
  pprint("Start time = ", foo);
  foo = Lookup(time, timeTolerance);
  pprint("Lookup time = ", foo);
  startTime = TimedIterationTest.EXECUTING.START + initialWait;
  pprint("Run to start at", startTime);

    // If either the "Start" or "EndCondition" lines below are uncommented, I do not get any printouts
    // past this point - not even "Iteration completed at"

Iterate:
  {
    //Start Lookup(time, timeTolerance) >= startTime;
    RepeatCondition i < repeatCount;
    //EndCondition Lookup(time, timeTolerance) >= Iterate.EXECUTING.START + iterationInterval;

    i = i + 1;
    pprint("Iteration", i, "at", Iterate.EXECUTING.START);
    pprint("Lookup   ", i, "at", Lookup(time, timeTolerance));
  }

  pprint("Iteration completed at", Iterate.EXECUTING.END);
}



To compile this, I'm using:
plexilc TimedIterationTest.ple

To run this, I'm using:
plexiltest -plan TimedIterationTest.plx



When I run, I get:

No simulation script specified; using empty script.
Running executive from /home/ugps/plexil-3
  Plan:      TimedIterationTest.plx
  Script:    /home/ugps/plexil-3/examples/empty.psx
  Libraries:
  Library directories:
  PORT:

Start time =  0
Lookup time =  0
Run to start at 10
Iteration 1 at 0
Lookup    1 at 0
Iteration 2 at 0
Lookup    2 at 0
Iteration 3 at 0
Lookup    3 at 0
Iteration 4 at 0
Lookup    4 at 0
Iteration 5 at 0
Lookup    5 at 0
Iteration 6 at 0
Lookup    6 at 0
Iteration 7 at 0
Lookup    7 at 0
Iteration 8 at 0
Lookup    8 at 0
Iteration 9 at 0
Lookup    9 at 0
Iteration 10 at 0
Lookup    10 at 0
Iteration completed at 0



If I uncomment the Start and EndCondition lines, I get:

No simulation script specified; using empty script.
Running executive from /home/ugps/plexil-3
  Plan:      TimedIterationTest.plx
  Script:    /home/ugps/plexil-3/examples/empty.psx
  Libraries:
  Library directories:
  PORT:

Start time =  0
Lookup time =  0
Run to start at 10



And just to be sure, I set iterationCount = 100000 so that it would certainly go over 1 second of execution time. Still I get:

...
Iteration 99995 at 0
Lookup    99995 at 0
Iteration 99996 at 0
Lookup    99996 at 0
Iteration 99997 at 0
Lookup    99997 at 0
Iteration 99998 at 0
Lookup    99998 at 0
Iteration 99999 at 0
Lookup    99999 at 0
Iteration 100000 at 0
Lookup    100000 at 0
Iteration completed at 0



Any help would be greatly appreciated. Thanks.
Chris



Chris Langley, Ph.D., P.Eng.
Senior Engineer, Guidance, Navigation, and Control
MDA Space Missions
9445 Airport Road
Brampton, Ontario
CANADA  L6S 4J3
1 (905) 790-2800 x4199