some questions about onboard program

[bgrain]

HI everone

It says that in ni-motion Each onboard program gets a default time slice of two milliseconds, after which it relinquishes control of the processor to the next onboard program or housekeeping task.what does this mean? a onboard program get 2ms time slice and it executes

once or several times  but how long it has to wait to execute again.in this case i wonder if the onboard program has determinism and if it can implement precise timed loop.Thank you !!!

[Rodj]

bgrain,

Onboard programs are guaranteed to run for 2 ms (though this time can be configured to be more or less) every Onboard Program Interval Period.  By default the Onboard Program Interval Period is 63 ms.  If the motion board is not busy with other tasks, the onboard programs may run more than this.  It may take several time periods for the entire onboard program to be executed.  This depends on the number of commands and how long each command in the onboard program takes to execute.

I do not recommend the use of an onboard program for implementing a precise timed loop.  But final answer would need to factor in what you determinism requirements are.

Thanks,

Rodger S.