7i96E Differental Step/Dir - SOLVED

Do you need to set any jumpers to run a 7i96E Mesa card in differential mode on the Step and Dir outputs? I wouldn't think so, and there is nothing indicated in the manual.

LinuxCNC is talking with the card, axis positions in joint are changing, the drives are powered, and the stepper rotors are locked/holding.

I know it is something simple, it has me stumped .

Whether the step/dir outputs are differential or single ended is entirely determined by
how they are wired

Note that by far the most common reasons that you don't get movement in step/dir
systems are wiring errors, step/dir swapped or too short step pulses
(start with 5000 ns)

PCW wrote:

Note that by far the most common reasons that you don't get movement in step/dir
systems are wiring errors, step/dir swapped or too short step pulses
(start with 5000 ns)

The manual for my drives state a minimum 2500ns for step, and 5000ns for dir changes. That is what I configured for.

I don't need extreme performance out of my hobby machine so I should be able to de-tune.

Is there a rule of thumb like 2x or 4x min pulse duration ? Should step and direction timings be set equal?

I see no enable cabling on your drivers...
Mike

In general you should _never_ use minimum timing numbers
I would always double the minimums to start and only reduce the timings
if they limit your maximum step rate.

Mike_Eitel wrote:

I see no enable cabling on your drivers...
Mike

Pretty sure those drives (like most low end step motor drives) have "DISABLES"
so will work when unconnected.

Was aware, but dislike unconnected (activated) inputs by principle

PCW wrote:

Mike_Eitel wrote:

I see no enable cabling on your drivers...
Mike

Pretty sure those drives (like most low end step motor drives) have "DISABLES"
so will work when unconnected.

That is correct, enables not required on these drives.

PCW wrote:

In general you should _never_ use minimum timing numbers
I would always double the minimums to start and only reduce the timings
if they limit your maximum step rate.

Yup!! doubled the step/dir times, motors are purring like kittens. I knew it had to be something simple.

Pretty sure generic Chinese step/dir drives are not tested at their minimum step length spec...