Mach3 & PMDX 134

[olf20]

I posted over on the warp9 board a problem that I
was having.
I had been running my mill with Mach3 062, ESS, PMDX 134,
and c25 bob.
Everything had been running fine so I decided to put everything
in my cabinet.
After putting everything in and wiring it up I was having trouble
with my limit switch inputs. After throwing a few questions to
Andy (at warp9) it appeared I was getting noise thus tripping
the limits.
Two things I found;
The first was I had installed a 5V buss panel to get all my 5V from.
I had hooked all the +5V for the limit switches to this buss thinking
that it would leave more area around the C25.
I had to move all the +5V back to the C25. Then I could at least get
M3 to start to work. I was still having some limit trips.

The second thing I found was that I had installed a switch on the front
panel so I could disable my drives if needed.
These two wires going from the PMDX 134 to the toggle switch was causing
the remaining limit trips.

All wiring going in and out of the box used shielded cable with the ground tied
to a center point in the cabinet.

Does everything have to be shielded???

Seems odd that the enable / disable wires would cause these problems.

Thanks for any advise

olf20 / Bob

[Steve Stallings]

The disable signal to the Gecko drivers acts locally on the PMDX-134
board and does not interface with the breakout board. They could
be acting as antenna picking up noise from one place and carrying
it to another and radiating it there.

In any case this sound like an issue with excess noise in the box.
Are you using a VFD driven spindle. If so, test to see if the problem
goes away if the spindle is not running. If this proves to be the
source of the noise, I would recommend being sure that the power
cable from the VFD to the spindle is shielded and that the shield
is connected to the safety ground at the VFD.

[olf20]

No VFD.
Box only contains 68V DC supply, ESS, C25, PMDX 134,
and 5V power supply from Jeff Birt.
The ESS must generate lots of noise as my radio in the
back of the shop squeals when I power up the box.
Thanks for the reply
olf20 / Bob

[Steve Stallings]

OK, no VFD.

I do see that the C25 board does not use opto-isolators, so you
should look at your system to make sure that placing the parts
inside the control box did not introduce any ground loops.

[olf20]

Does PMDX have a board to interface to the ESS to bring out
all the I/O??
Thanks
Bob

[Steve Stallings]

Our PMDX-126 works well with a SmoothStepper, but really you
should be able to find the problem without having to buy a new
board.

[olf20]

Hi Steve
Back again.
I found a ground loop in the system. Fixed that and system
is better. How ever when I leave the system on overnight
(and sometimes during the run) I have a "limit switch triggered.
What is generating the noise???
Do I need to put a metal shield between ? and ?
Do I, could I use ferrite cores to help.
I have isolated the inputs with a relay board.
I don't mind spending some $$$ if I knew what to
spend it on.
Thanks again for any help!!!
Bob