Fixed Cyclic Execution of Motion Tasks

[collinsd70 30]

Hi All.

Im currently developing a machine program from 2 previous machines- this means im integrating routines from both projects including standard and motion logic.

My question however is- 1 program is scanning its motion tasks on a preset cyclical value- whereas the other motion program is not set with any priority.

I have worked on programs before (mainly Mitsubishi) where we used fixed priority and scan times to ensure no high speed signals werent missed (like encoders for example).

Would anyone be able to give me some advice with regards to the motion tasks? What are the advantages/ disadvantages?

[Ken Roach 194]

In general, the motion controllers and the motion subsystem of the Logix operating system take care of interrupts and motion planning by themselves.  As a programmer, I just try to keep my other program tasks from taking up too much processor bandwidth.

I usually use a relatively fast cyclic task (5-10 ms) to hold my motion control routines, because I want to be able to react quickly to motion-related events, like the completion of a move or a change in gearing or dynamics.

[collinsd70 30]

Thanks Ken- very useful to know.