Reverse Engineering Stepper drive

[Karl_T]

I'm looking at purchase of an old CNC tool and cutter grinder. Control still runs but has problems http://tinyurl.com/g4wwb

If I purchase, I would need to record what each cycle does in terms of stepper pulses. And then convert this to a math equation for an eventual new control.


Is it possible to capture stepper pulse output back to a computer and analyse the data? How would I go about this?

Karl

[gar]

061008-0915 EST USA

Karl_T:

Determine the highest pulse rate that can occur. Possibly use a scope.

The minimum time between pulses is going to determine how fast your monitoring system will need to process data. Also determines the frequency of your master clock. The number of simultaneous channels to be monitored also determines your processor speed.

Suppose you have two channels and the maximum pulse rate is 10 kHz and you want to resolve time information to 10 microsec.

Both channels can be monitored simultaneously. You need a clock that is quantized to 10 microsec. All processing of data must occur within this 10 microsec period.

You would use a parallel port to monitor the two channels.

You create a test loop that continuously looks at the parallel port. If either channel has a positive transition, then record the state of both channels and the current time from your 10 microsec clock. This is saved to memory.

You want to work in assembler, direct machine language.

Later you process the saved data.

.

[Karl_T]

Oh boy,

I'm pretty good with computers but don't do assembler. I'm sure I could analyze the output data.

By chance, would anybody like to do this for hire?

[jphagen]

You can use the sound card to monitor the signals.
Look for one of the free programs, it should be good to
20+khz