Cant get step/dir drives to move 7i92-7i76

tommylight wrote:

What are the step time and step space set at ?
Set them to 5000 at least till you get some movement.

Yeah, I tried at 5000, 3000 2500 2000

Either I have it configured wrong in configs or drive is not setup properly or I have it wired incorrectly.

wiring is not complicated differntial step+ to PP+ step- to PP- dir+ pd+ etc.... So I think the wiring is ok.
The drive is set for step and dir,
I think the voltages dont make sense what I measured , what PCW was talking about. i think the measurements are wrong.

Think I need 24v on PV ? The other drawing shows 24v opn PV for single ended and doesnt show 24v on P for differential.

bevins wrote:

PCW wrote:

What I meant was to measure the direction signal voltage to see if itchanges based on jog direction

from gnd to dir- it stays at .4v if I press left arrow it goes to 4.5v, press right arrow it stays at .4
from dir+ dir- it is at -4v if I press left it goes to 4.2v, if I press right it stays at -4v.
from gnd to dir+ it stays at 4.4v, if I press left it goes to .3v If I press right it does nothing.

I don't think that is correct.

Sounds about right

Is it possible the drive is not configured for step/dir mode?

PCW wrote:

bevins wrote:

PCW wrote:

What I meant was to measure the direction signal voltage to see if itchanges based on jog direction

from gnd to dir- it stays at .4v if I press left arrow it goes to 4.5v, press right arrow it stays at .4
from dir+ dir- it is at -4v if I press left it goes to 4.2v, if I press right it stays at -4v.
from gnd to dir+ it stays at 4.4v, if I press left it goes to .3v If I press right it does nothing.

I don't think that is correct.

Sounds about right

Is it possible the drive is not configured for step/dir mode?

I checked the drive and it is set for Position Pulse Control is what they call it.

PCW wrote:

bevins wrote:

PCW wrote:

What I meant was to measure the direction signal voltage to see if itchanges based on jog direction

from gnd to dir- it stays at .4v if I press left arrow it goes to 4.5v, press right arrow it stays at .4
from dir+ dir- it is at -4v if I press left it goes to 4.2v, if I press right it stays at -4v.
from gnd to dir+ it stays at 4.4v, if I press left it goes to .3v If I press right it does nothing.

I don't think that is correct.

Sounds about right

Is it possible the drive is not configured for step/dir mode?

The manual says it works ion differential or single ended like the pic below. Maybe some weird quirk it doesn't work differential.
Plus what looks weird is the single ended needs 24 volt supply and differential doesnt....

If I look at the drawing, it seems the dir pulse needs the 3k pullup which means I would need 24v on PV at all times. no?

No, it should work as is. The 24V is just for a 24V open collector driver

Is the drive enabled?

PCW wrote:

No, it should work as is. The 24V is just for a 24V open collector driver

Is the drive enabled?

Yes, it gets enabl;ed with machine-is-on.
The servos engage and you can't turn the servo motor by hand.

I guess I will try single ended.

bevins wrote:

PCW wrote:

No, it should work as is. The 24V is just for a 24V open collector driver

Is the drive enabled?

Yes, it gets enabl;ed with machine-is-on.
The servos engage and you can't turn the servo motor by hand.

I guess I will try single ended.

If the differential inputs can be driven by a 26LS31 (as suggested in drive manual)
then the 7I76 outputs should be fine.

Can you make the drive step by connecting PP+ to 5V and grounding PP-?

PCW wrote:

bevins wrote:

PCW wrote:

No, it should work as is. The 24V is just for a 24V open collector driver

Is the drive enabled?

Yes, it gets enabl;ed with machine-is-on.
The servos engage and you can't turn the servo motor by hand.

I guess I will try single ended.

If the differential inputs can be driven by a 26LS31 (as suggested in drive manual)
then the 7I76 outputs should be fine.

Can you make the drive step by connecting PP+ to 5V and grounding PP-?

I'll be at the shop later today and will try that.