PMDX 126 BOB Setup
 

In this thread I am going to talk about the PMDX 126 BOB in detail. I have a Kitchen Table project setup to show the basics of the wiring. The busiest thing going on at the moment with this setup is the Bi-Polar Parallel setup of the motors. This particular setup will have the PMDX-133 boards and will show in a basic configuration that the PMDX-126 has almost no wires running from it. I have the 470K resistors for the motors attached on the 133 board. I am also going to do this setup Half-Coil and use the resistor that lmits current to 4.5 Amps. I have been testing the 6.3 amp setup today and the motors so far are only warm to the touch.

1. PMDX-126 (Charge Pump Enabled)
2. 2 - PMDX-133 Boards
3. 2 - 18 Inch Ribbon Cables
4. 4 - Gecko 203V Motor Drivers (5th one in photos not hooked up)
5. 1 - 4n48R12 (Yes 400VA) Power Supply (Note 12 volt feed not needed)
Note: Future PS I am ordering are 5n48 with no 5 or 12 volt feeds. I will have the Fuse block added and the transformer will have the leads for 12v and 5v if folks ever need to add that to the system.
6. Power Feed - The BC01 is what I am using parts from for this test. I currently have a 15amp Breaker where the rotary discinnect is normally. I do have the contactor and power switch wired for this test. I am feeding 110V at this point for the testing.
7. 4 - 640oz 8 wire motors.
8. 2 - HeatSinks for Geckos

hey Mike! this is pretty much the exact setup i'm running right now, and i was wondering if you could take a few more pictures of the wiring, so i can double check that things went where they were supposed to? I've gone through other posts, but you are the first that i've seen that has the exact same setup.

Smooth Stepper
 

what is the best way to connect the pmdx-126 to the PC? Is anyone using the smooth stepper?

Hi Hurshy,

I've got a PMDX-126 with a smooth stepper riding piggyback on the 126 card works like a champ. Don't have to worry about computer issues. If you are looking into the smooth stepper, make sure to get the ethernet smooth stepper and not the USB version. Connect your your PC to the smoothstepper via standard Cat5 or shielded Cat6 if you are concerned about interference. The PMDX-126 with the Ethernet Smoothstepper is an excellent combination for stability. The only thing I think you loose is the automated setup of imputs through Mach3 from my experience. Good luck!

Which Brand
 

What brand of smooth stepper did you purchase?

Mike aka Metalhead

I see in some photos all 8 wires are brought back to the circuit board and connected. In others I see that they are paired up and soldered and a single wire brought back and connected to the circuit board. Is their any reason to do one over the other?
How are you doing with your build?

5vdc secondary
 

MetalHead

I see in your photo of the power supply that you have a 5vdc secondary. If you have one I would be interested in purchasing it. If not do you have a supply source? I don't see it on the Antek website.

The wires back at the PMDX are just for testing. Once installed only a sigle wire for each pair comes back to the bob.

I do have a secodary card, but it is 12 volts and you have to have a transformer with windings to support that. I found this was not needed once we moved to the 126 boards. What are you trying to power?

Power Supply
 

Metalhead
I am trying to power the smooth stepper. It is 5vdc, I have decided to use the DIN Meanwell 5vdc module.

I do have another question. I have attached a picture of the Antek PS-5n48 and the fuse holder that came with it. Do you know the location to connect the blue and green wires?

Also since the transformer has two sets of wires on the input side. Am I correct in saying that I should screw the unused black and red wire down to the DIN terminal blocks and just not use them.

Sounds like you have twin primary windings. This is common so that you can wire them in parallel for 115V input and in series for 230V input and get the same output. You probably want the two black wires together and the two red wires together, but check this with your supplier. Here's a manufacturer's page that explains a bit.

You using the 126 Board? I think you can power off of one of those outputs. But I would ask Steve at PMDX this question.

contact points
 

Metalhead
what is the red/white/green button connected to?

It is wired to the contactor. That button (Red/White/Green) is the power switch that is mounted on your control box. It is wired through the coil on the contactor and engages the contactor.

does that translate into putting the switch inline with one of the inputs to the coil of the contactor. I tried it and that didn't work. So I tried it with the other line. That also didn't work. I also wonder if the switch is working (or did I put the switch together correctly). These switches remind me of Lego for engineers. Before I try putting this parallel to the contactor coil I am going to wait for more input.

The red/white/green should actually be two switches (and optionally a status lamp behind the while). The Green should be a normally open switch, and the Red should be a normally closed switch. You will need to wire the two switches to both the coil and the aux pole of the contactor using a specific circuit.

Look here and click through to here and here.

Thanks for the link to the wiring diagram
I guess I was right when I said Lego. I searched the site for references to BC01 and found that this switch is indeed made up of a BC01 and a BC10 switch. That answers a lot of questions. What holds and powers the light bulb? The BID switch? http://i1296.photobucket.com/albums/...psff91d345.jpg

ahhhh! diagrams look like a short circuit. Does anyone have a photo of the back of the switch and contactor wiring. It would really make it lot easier for us greenies.

Yes, the BID is the indicator lamp. Time to stare at those wiring diagrams until it starts to make sense.

The basic idea is that the contactor holds itself in via a circuit that comes from one side of the supply voltage, runs through the aux contact to the coil, and back to the other side of the supply to complete the loop.

That circuit only works if the contactor is already pulled in. So the normally open switch (BC10) behind the green button completes the circuit when the the contactor isn't yet pulled in.

The normally closed switch (BC01) is used to break the circuit and shut off the contactor and everything fed by it.

The Indicator lamp(BiD) is fed by the active side of the coil (only when it is hot), and returns to the other side of the supply, so that you can see when things are on.

All of that is on those diagrams, so keep looking, and it'll snap in place for you very soon - note that those pictograms on the side of the BC01 and BC10 for NO and NC switches are similar to what you see on the diagrams. You probably will have had this "click" before I finish writing this ...

Contactor Blues
 

ok, here we go again. Here is the contactor I am using. I take it the far left connections are not used. Is the area I marked "are these two connections used" point "13" and "14" in the diagram? I downloaded several of the companies brochures and did not find one that had an internal diagram.

http://i1296.photobucket.com/albums/...psee7c5250.png

Ok I think what you need to understand is you have two things going on here.

Power that is coming in and out on the "L" lines and that red box you marked is the coil mechanical circuit. Take a meter and check , but what those side connections are is the top two are one state (Closed when the contactor is open) and the bottom two connections are another state (Closed when the contactor is closed)

If you set this contactor up and play with powering just the coil, it will help you understand how the contactor works. Use the diode setting to get a tone to see how that side circuit is working (Top and bottom connections).

When you press the on button (Momentary Switch) power is moving through the switch from the off button leg (Power from L1) down to "a2". This charges the coil drawing the circuit closed. Once closed (or latched) power flows through the coil (via 13 and 14 (or the lower two in that circuit) being held closed) and since the coil is mechanically connected to the "L" polls, it hold them on (Latched) as well.

When you press the off switch the power loop is broken between L1 and a2(as well the side circuit because of the mechanical connection). This releases the latch allowing power to disconnect because the contactor is spring loaded.

You can hook a plug on the output side of the contactor and plug in a lamp.

Do not hook up any down stream electronics until you know how this circuit works. I would also go ahead and wire in E-Stops in series off that Fuse back to the off button so you can see how 2 or three of them can also stop power.

Be safe when working with electricity, safety is your responsibility !!!!!

Contactor Working
 

Thanks all for the help. Once I found out that the connection points were not the screws at the top of the device but the set right below them it worked. Push green for power on. Push red to break circuit contact, thus relay falls out and device powers down. Again thanks.
Now that it is working I need to wire in the emergency stop boxes. I no longer have all the parts for them so I will need to purchase replacement parts.

Using PMDX-126 to Power ESS
 

It was mentioned that the PMDX-126 can be used as the needed 5VDC power supply for the smooth stepper. I did the research and found that the USB version can use the on board power but the Ethernet version must use an external power source. Jameco sells a DIN power supply for about 17.00. I have used it and it works fine.