FINAL REPORT

It works exactly as advertized! Hurrah! My stepper motor has been running now for about 200 hours via this threads scenario.

My particular application proved a bit more complicated as the module I'd been using was OO with a number of hashes, one of them quite large. And I find that the threads module gets kind of complicated if you try to OO-ify things. Still, not to worry. Quite easily gotten around, that.

Most of that OO business was for non-stepper motor related issues: data and solenoid channels of the LabJack device. OO was by no means required for running the stepper channel as a separate consideration.

So for the stepper motor I pared things back to essentials: just the basic (non-OO) module Device::LabJack. And that part only did I put into a thread with only the absolute minimum of shared scalars.

Once simplifed in that manner it ran like a champ. The Tk GUI is lively again. Excellent suggestion. Thanks Zentara!