I've been having an issue recently where on longer programs, occasionally I'll have mach 3 stop, with the spindle still spinning and no axis movement.

I then can't do anything until I close out and restart.

It is happening randomly,  and well past the licensing limit (this is indeed a paid copy)

I've ran longer codes, and even the same code before without issue.

Mach3 is running on an xp computer with parallel port to a break out board

Reset isn't flashing.

Watchdog timer has been turned off

Debounce has been set to 500.

Screensaver is disabled.

It also appears I'm losing steps in at least one direction, but I can't tell if that's a symptom or a cause.

Any help would be appreciated.

Hi,
that sounds like a 'run out of data' issue.

Mach is the trajectory planner and it sends blocks of numeric P(osition) V(elocity) over T(ime) data to the motion controller, in your circumstance the parallel port
driver. These blocks of data are stored in a buffer and the motion controller consumes one time slice, or data packet, every 1 millisecond.

Hopefully Mach can keep up and send enough data packets to keep the buffer full. If however Mach gets bogged down or some other software prevents Mach from running
at timely intervals then the buffer will empty and the motion controller wont have any data and will not know what to do and stop. This is called a 'run out of data fault'.

One simple expedient is to increase the length of the buffer. Machs parallel port has, if memory serves, a 500 millisecond buffer. You might try increasing that to 750 ms
and see whether that helps.

I use an Ethernet SmoothStepper as a motion controller, and it relieves the PC of having to generate pulse streams, for which PCs are notoriously poor, and so can run
the buffer at well under 500ms, in fact I have it set to 180ms, but I have reduced it further on a trial basis down to 100ms, all without encountering the dreaded
'run out of data' fault.

A good external motion controller will markedly improve the smoothness of operation, increase the reliability in face of competing software while additionally allowing the use
of 64bit OS's like Windows 10. Do yourself a favor.

Craig

Thanks Craig, that sounds like the next step then. I appreciate the help

Hi,
when I first started eight-nine years ago I used Mach3 and a parallel port, then two parallel ports. By-and-large I had good results and so I resisted the advice about
buying an expensive, or at least so it seemed, motion controller. After all what could I possibly gain over a perfectly satisfactory parallel port solution...right?
Wrong, I did buy an Ethernet SmoothStepper, mainly to be able to use Mach4, but the truth is that an external motion controller is just that much smoother and more stable than a
parallel port that I could immediately increase my rapids by 33% and still not lose steps, and the steppers seemed to run cooler.

I have been using Mach4 for seven years now, and its all but essential to have an external motion controller to use and get the most from Mach4, so I have great respect and confidence
in my ESS. I paid $180USD seven years ago and I've used ever since. The best and cheapest investment I ever made in CNC.

Craig

Sounds like a worthwhile update. I've ordered the ESS and am looking forward to is delivery!