Dirk, Mike and Gerald.
Mr Stallings was quick to point out the 15ma spec to me and was concerned that a full current (if using a 201/202 series gecko) you may have an issue. The 203V, which only uses as you mentioned 2.5ma, shouldn't care. But, at this time it hasn't been tested thoroughly enough to guarantee performance. My biggest concern is that I am building 2 machines- maybe 3. I have 3 fabrication facilities and I want to support the machines, not babysit them :) I just want it all to work.

So, to error on the safe side...I took Mr. Stallings recommendation to go the 2 card route.

All my best.

Sean

Dirk, it was the 15mA issue. There was a heated discussion on the gecko-drive forum. Those guys are in the business of selling boards and they don't like any scheme where you can save a board :)

Hahaha.

Sean, I didn't see your post when I made my last one. So you spoke to one of the boardsellers? :) What can there be to test????!!!!!

Hahaha - ditto Gerald.
Yes, sir - purchase another board. :) Of course, that is only IF I need it.
I am building the controller with a single board and room for 5 gecko's. I don't plan on commissioning the MM with the indexer from the beginning. Just making allowances for it. You bet I will just do a quick gecko drive add to the heat sink and a quick input rewire first before I order another board! I just wanted backup plan if my first one went the way of the DoDo bird. :)

I hope all is well in the Shark Capital of the world. I was watching on Discovery Channel last night your lovely town and the surrounding areas. I now want to move.

...with a last name like Reish.....I could finally use the German I grew up with :)

Over on the geckodrive yahoo group, someone discovered that his breakout board (not a PMDX) was limiting the top speed of his motors. I asked Steve to tell us what the top speed of a PMDX-122 is. His reply at the geckodrive yahoo group:

"The PMDX-122, PMDX-121, PMDX-132, and PMDX-131 use 74ACT
buffers in the Step and Direction signal path. There are no opto-couplers
in these signals, because these are provided in the Gecko drives. While
these buffers can function at very high frequencies, I generally recommend
1 MegaHertz as a practical limit. If your machine is failing above 55KHz,
then I would feel relatively confident that the limitation is somewhere
other than one of the breakout boards listed above.

As best I know the breakout boards from Campbell, Sound Logic, and
CandCNC are similar in this regard. Some of the CNC4PC boards are
also buffer only devices, just not the one you have.

Our older PMDX-120 boards are a more complicated case. They have
a lot of features to allow for step pulse modification and the frequency
limit would be determined by mode selection. At the time they were
designed 40 KHz was the highest frequency provided by any available
software. It will work at higher frequencies, but pulse widths will be
affected.

For customers that actually need a board with isolation of the step and
direction signals, we recommend putting one of our PMDX-103 boards
between the computer and the breakout board . This board is designed
for high speed operation, up to 1 MHz, but does not have the high current
output to run Gecko drives directly."

We will not run into speed problems with the PMDX-122.

Further from Steve:

"We ran a test today up to 2 MHz on a PMDX-122 and there was essentially
no signal degradation, but because we fear problems with cable quality and
signal reflections, we are going to claim only 1 MHz when we publish this
specification."

PMDX E -stop
 

Please explain to me what the action will be if i push the E-stop configured via the PMDX 122 instead of E-stop that kills all method.
I have read discussions on the fear and danger of changing cutters and relying on the BOB but i did not notice extra switch that cut the power to the spindle if you need to change the cutter, is the solution to cut all power to the MM for cutter change

The E-Stop acting only on the PMDX will stop all the stepper motors at minimum.

The Spindle/Router's start/stop should be controlled from an output on the PMDX. Typically the built-in relay is used. So, an E-Stop to the PMDX should disable that output (open the relay) and stop the spindle/router.

But relays do go faulty and stick closed . . . . not a risk for cutter changing because the spindle/router will be turning and you will not put your hand near it.

The danger is not the E-Stop. The danger is when something makes the spindle start up when it is not supposed to. We have seen that happen (when interference duped the charge pump), and the only way to be totally safe is to remove mains power.

However, I bet you anything that the guys in the workshop today change a cutter if they see the spindle is stationary, and they don't bother to switch off mains power.

A disconnect switch on the y-car, similar to the door switch, that cuts the leads between the VFD and the spindle, seems to be the safest way to go. . . . until a bright spark uses that switch to stop a running spindle and damages the VFD. (Okay to disconnect a stopped spindle, but not a running spindle).

Thank you Gerald, this also explain Estop and PMdX good
http://www.mechmate.com/forums/showthread.php?t=665
The safe way to change the cutter would it not be to disconnect the power to the VFD?

Yes, the safest way is to disconnect power to the VFD.

Hi!
It is difficult to see the photos, but do I need female connector to PMDX card?
I've Ordered paralell PCI card to my PC, where I must have female contact.
I bought a printer cable with female and male contact.
If PMDX need female contact, I must have printer cable with female connector at both ends.
What do you use?

See my cable:

Your cable's connectors are correct.

This is the PMDX-122 connector:

http://upload.wikimedia.org/wikipedi...ronics-36F.jpg

See:
http://en.wikipedia.org/wiki/Micro_ribbon

Thanks Gerald
My technical english is not good, so it is difficult to search the Internet for such questions.
So it's good you understand my question.

Svein, I understand your English better than many people who have English as their first language. It is because you try harder to explain in short sentences with simple words.

When I am in a non-English country, I understand instructions much better from from people who try their best to speak a little school english to me, because they speak slowly and say each word clearly. When I am in England, Wales, Scotland, Ireland, America, Zimbabwe and with some people in Asia, they tell me that their home language is "English", but I can hardly understand what they are saying because they talk so fast and use strange accents.

So, no need to apologise for your English - I like it!

I must apologise for not knowing even one word in Swedish, and I have visited your country less than a year ago.

Power supply to PMDX-122
 

I'm not Swedish Gerald, I'm Norwegian. :)
I have a question.
My PMDX-122 has arrived, and I will buy power supply to this.
To make it easy, can I use this??:
http://www.altitec.no/product_info.php?products_id=7009

230VAC-9VAC (not adjustable)
Capacity: 20.0 VA 2.1 A
Is VA and A ok?

Svein,
The 9VAC output is just right for the pmdx. It is more power than needed but will work fine. :) Check page 18 of the pmdx manual for the proper connection points.

Thanks
I buy this I think.

Mr Norway Svein, (sorry), that transformer looks 100%.

The PMDX-125 is scheduled for release in June '09:
http://www.pmdx.com/BreakoutBoards

It looks as if the new pmdx 125;
runs on mains power instead of 9v.
has more accessory relays for router/vacuum/dust collector
http://www.pmdx.com/BreakoutFeatures

I am sure that the PMDX-125 is intended to replace the PMDX-122 in the course of time. Personally, I would only look seriously at the PMDX-125 after it has been on the market for about a year and has been thoroughly de-bugged. By which time there may be other products that are more USB (and proximity switch) friendly.

I would love to see a PMDX-product that is:
- USB
- Mach or Linux(EMC) compatible
- Mains 230 or 115V
- capable of stringing proximity switches in series
- capable of all the standard BOB functions we already have (E-stop, charge pump, couple of relays, etc.)
- small, but not tiny.
- fitted with pluggable connections for quick board swops.

I have a question regarding the PMDX, its not MM related, I have one in my tiny weenie router :) if this is not allowed, please delete this post I fully understand.

I have the pmdx almost fully configured, the only problem Im having is configuring the relay to act on M3, M4 and M5 commands.
I configured Mach3 motor outputs, enabled the spindle (step & dir pins set to 1 and step & dir port set to 1) also set the relays for direction both 1 in the spindle setup tab.

The problem I have is:
I can enable the spindle (metabo grinder) by issuing M3 but I cannot stop the spindle by issuing M5, the only command that stops it is M4. How can I stop it using M5???

Thanks!!

found the solution :) I confused things and mixed spindle with relay, what I needed to do was to enable output #1 and configure the relay settings for CW and CCW in the spindle setup tab.

E-stop and outputs
 

I think I know the answer allready but I would like to have a confirmation to be sure.

On the PMDX website I found this for the PMDX-122
"Inhibits outputs when E-Stop or Fault inputs are asserted"

If the E-stop is activated on the PMDX-122 will this than also deactivate all the outputs?
If I have a contactor coil connected to the relay on the PMDX-122 will this contactor open if the E-stop is activated?

The E-Stop controls the on-board relay. Here is some information from Section 3.4.2.1. (page 17) of the PMDX-122 manual:

When either (or both) the E-Stop (active high) or Fault (active low) inputs are asserted, the following actions take place:
• The ACK bit in the PC’s status register reads as a “1”
• The LED labeled “E-Stop active” (reference designator DS10, near J6) is “on”.
• The LED labeled “Outputs Enabled when lit” (reference designator DS1, near the center of the board) is “off”
• The control outputs are tri-stated with a weak (10K ohm) pull-down
• The relay is de-energized
• The data bus outputs may be tri-stated with a 2.2K ohm pull-up, depending on the setting of jumpers JP2 (see section 3.1.3) and JP5 (see section 3.1.4)

Mike,

Thanks for pointing this out. I must have overlooked it in the manual.

"The control outputs are tri-stated with a weak (10K ohm) pull-down" Does this mean that all the other outputs on J8 (non relay) are also deactivated?

Bart,

Figure 4 on page 9 shows that the step/direction signals are deactivated whenever the E-Stop switch is opened.

Figure 5 on page 12 shows that the signals going to J8 are also deactivated when the E-Stop switch is opened.

The 10k resistors will still pull the signal to a LOW level, but at only 0.5mA. SOME input circuits driven by J8's outputs might work at 0.5mA. MOST TTL type circuits need a minimum of 4mA to work properly. Because I normally add opto-isolators, to all outputs, the E-Stop would work perfectly for my use. Opto-isolators require about 10mA of current to turn on the internal L.E.D.

Hi anyone printed circuit board design interface for stepper motor controler is?

NGH,
The pmdx is a manufactured product, not a DIY type kit or available as plans. If you are interested in building your own, www.pminmo.com has some free plans that are available.