Re: General Question REgarding Stepper vs. Servos

Thanks Tim. As you indicate, there's definitely more to it, but
what the heck: it works. Charles

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Tim Goldstein" <timg@k...>
wrote:

> Charles,
>
> No, closed loop has nothing to do with it. What you have to have

is a

> DOS program that is using a virtual port and not direct port

access.

> There are some 3rd party applications that will allow you to

access the

> port from a command shell (it is really not DOS, but a virtual DOS
> emulation. Way off list and too nerdy to get into it here, but

trust me

> it is not DOS), but they have very high latency. Now closed loop

and

> high latency is a bad thing. You have the software correcting

position

> in real time and a queue of position change commands that have not

yet

> been sent to the drive. Causes great instability.
>
> Apparently what you are doing is working for you and you are happy

with

> it. I would not recommend a DOS program under any of the NT based
> operating systems as a general rule.
>
> Tim
> [Denver, CO]
> Sherline products at Deep Discount
> Mach1 & DeskCNC with credit card ordering
> www.KTMarketing.com/Sherline
>
>
> > -----Original Message-----
> > Hey Tim, I AM running a DOS program through WinXP without

errors -

> > no program errors, no machining errors. I have access to my
> > parallel port, the encoder and the motors. I believe, but am

not

> > absolutely sure, that a closed-loop system is a necessary part

of

> > this type of setup. Refer to message 62087 and subsequent

threads.

> > Thanks Charles