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I purchased the MB2 breakout board to use with my UC300ETH.
http://www.cncroom.com/break-out-board/smooth-stepper

It's designed to supply 5V power to a Smoothstepper through pin26 of the ports.
Can this power the 5LPT, or should I use an external supply?
And how should the jumper be set on the 5LPT?

The 5 LPT board is the same for both the USB and the ETH version. To use the external power option, jumper J1 should be set to 2-3 positions since the Ethernet cable does not have +5V, like the USB. I modified my card, removed the plug because it is not very well located and I hard wired the power supply connection internally in my control box. Any external +5V supply can be used as long as it is at least if it can deliver enough current to supply everything on the card. There are a lot of outputs, so my guess is that at least 2A is necessary if and in case all inputs and outputs are used. This is not very well specified in the UC300ETH or USB manual. In my opinion, especially the UC300ETH manual should go through a serious rework. Too much concentration on the Ethernet part and almost nothing relevant on the hardware itself, electrical specifications are missing and also a lot of other things. Some of the information is in the UC300USB manual, some in the UCCNC software manual... so, in my opinion it is a bit of a mess.

That's not what I asked.
I want to know if it can get the 5V from the breakout board, through pin 26 on the ports, without using an external power supply.

It should work, I'm just not sure what happens to the reverse polarity protection P-Mosfet in the power input circuit, will have to look that circuit up.

ger21 wrote:That's not what I asked.
I want to know if it can get the 5V from the breakout board, through pin 26 on the ports, without using an external power supply.

Sorry I answered the questions you did not ask. The short answer is yes, but what I wrote is important in that respect. So, while what I wrote was not what you asked, you should read it and check it out. I have no idea about the current capabilities of that BOB.

I just heard back from CNC Room.
The MB2 board can supply 500mA through pin26 via an isolated DC to DC converter.
Is that enough power for the UC300?

I'm just not sure what happens to the reverse polarity protection P-Mosfet in the power input circuit, will have to look that circuit up.

I don't want to damage the board. Should I just cut the wire to pin 26 and power the UC300 from a 5V power supply.

ger21 wrote:I just heard back from CNC Room.
The MB2 board can supply 500mA through pin26 via an isolated DC to DC converter.
Is that enough power for the UC300?

I'm just not sure what happens to the reverse polarity protection P-Mosfet in the power input circuit, will have to look that circuit up.

I don't want to damage the board. Should I just cut the wire to pin 26 and power the UC300 from a 5V power supply.

Sorry, I did not find the time today to check the circuit, will do it tomorrow as it is already very late night here.
And I understand your question, just don't know the answer yet.
The only possible issue I see is the reverse polarity protection mosfet, I'm not sure what happens to that device if you connect it up like that, will have to check the circuit to make sure it will not damage.

ger21 wrote:I just heard back from CNC Room.
The MB2 board can supply 500mA through pin26 via an isolated DC to DC converter.
Is that enough power for the UC300?

No, it's not enough. That is... it depends on how you intend to use it and how you connect it. The UC300 has 36 digital outputs, each capable of sinking 20mA. It has also 2 analog outputs with unknown current capabilities, but let's assume 20mA. In total, just for the outputs you will need 760mA plus what the rest of the boards require. Of course, if you never load the outputs more than 10mA than 500mA is enough for the outputs, but the rest needs to be checked. Also in a more realistic case, not all the outputs are on all the time... but strictly, technical specification wise 500mA is not enough to run the UC300 boards, regardless if you'd have USB or Ethernet interface on them.