RE: [CAD_CAM_EDM_DRO] Gecko ERR/RES Handling

The only documentation that I know exists on the positive going steps
issue is what I replied to. I hadn't run into the problem before I
switched PC's out in my shop. The faster PC brought the issue to the
front burner as I was testing, prior to shipping on one of my milling
machines, a newly assembled G320 servo unit. It worked fine on my old
computer during bench testing but was quite prone to faulting on my shop
machine. Then I started trouble shooting because I hadn't run into this
before. After a logical process of elimination I concluded that it had
to do with the opto coupler and signal type and proceeded to change the
type pulse and it cleared it right up. I called Marris a few weeks ago
to let him know what I discovered so if other customers ran into this
software problem he could advise them of the solution.
Myself I don't use any pull up resistors on the step and direction lines
and have had rock solid performance on a the GX0 amps/drivers. The only
other issue that I know of with the Geckos' G320/G340 is the question
about the encoder noise when using HEDS type read heads. But I have run
my own tests with 100 ft of cable and no line drivers and no added
capacitance and also found rock solid performance. But noise and
faulting are two different problems and show up differently.
I have had excellent support from GeckoDrive. But as one that also
provides support for the Geckodrives that I sell, I can understand that
it is difficult for a customer to isolate a problem when there are so
many factors that could cause the problem. Doing it by telephone or my
email is challenging.
That is what is so good about CAD_CAM_EDM_Dro group is that there is
always someone that can help.
Dan

-----Original Message-----
From: David Eldredge [mailto:techdave@...]
Sent: Monday, December 17, 2001 5:33 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: Re: [CAD_CAM_EDM_DRO] Gecko ERR/RES Handling

Dan,

I think you are onto something regarding the positive going step pulse.
Dad
and I fought the geckos for a couple of days a couple of weeks ago,
faulting
all over the place, trying to get acceleration ramping right etc. It
was so
frustrating. Dad is growing to have a strong dislike for the Geckos,
after
having so many problems in the past with the earlier bug ridden drives,
and
another bad experience he had with the Gecko company.

Finally Dad did just what you did and flipped the direction of the step
pulses so that they were positive going and then things seemed to clear
up.
We were both so exhausted, I don't think we thought it all through,
since
Dad was focused on another problem relating to this in which his control
was letting the step line float with only a 10 k pull up resistor on its
input. Earlier drives he used in his system did not load down the step
input line. He suddenly realized that the 10 k was not enough to pull
up
the input to the Gecko and so he reversed his whole scheeme and then
reversed the step pulses so that they were positive going. Things then
started to work better, and we finally got things working.

Is there anything documented on this? Our Gecko experience has been
very
frustrating all around, and I don't know if Dad will go back to them
again
or not.

I am glad Marris fixed the error/reset line problem.

We were trying to get real fast rapids (not machining) and we did not
care
much about the error then. Of course .01 " of error would have been
unacceptable machining.


Dave