Control a plasma cutter : Modbus or CPC ?

Started by Xylotica, January 27, 2016, 10:38:20 AM

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Xylotica

The Hypertherm representative is proposing two versions of the plasma cutter we want to purchase :

-One with a "ModBus ASCII serial protocol"
-One with a "CPC" port

I understand that the "Modbus" allows to control more parameters like arc intensity and air pressure, but first and foremost, I want to be sure that these connectivity types are compatible with the KRC2 controller.

I'd also like to know what kind of hardware will be required to make the connection.

Cheers,

Johannes @ Robots in Architecture

Hmmm... I just quickly googled it and CPC seems to stand for "Circular Plastic Connector" which does not really give any information on the protocol. I would ask for more details here, maybe it's just a few digital/analog IO lines.
You can find many ModBus tutorials online, personally I would try to get it working with a Arduino first and then integrate it with the KRC2 serial protocol. In a worst-case scenario you can still use the Arduino between KRC2 and cutter.
Sorry that it cannot help with the decision. Try asking your vendor for integration manuals, sometimes the "consumer" manuals don't include information on such ports.

Best,
Johannes

Xylotica

#2
I found the documentation for the two types of connections available between a CNC and a Powermax.

The "CPC" is what they call the "Machine interface port" and seems to be an analog port which has one input (Start plasma), and two outputs :
-One is the "Arc transfer" which tells the CNC that the arc is established and that the motion can start
-The other is the analog information of the arc voltage, (divided by a certain value)

It "lools" like it can be connected to a serial port, but the "voltage divider" output is at 18V max (with a 1:50 ratio) ; isn't that too much for a computer's serial port ?

The "Serial Communications with ModBus ASCII" looks like a digital communication protocol which would force me to take a year's leave off my job and retreat in a lost budhist monastery to learn.

I have no idea what the KRC2 would do of this data anyway ; not much I suspect, from the near-vacuum that is yielded when Googling "Kuka" and "ModBus" ...