Proprietary CNC router FW migration fo Beckhoff

Hi

We are considering migrating our proprietary CNC router machine controler to Beckhoff stack.

We are now using QNX PC with Canadian ISA IO cards and in house developed firmware With Canadian Gcode interpreter and motion library.

We would like to migrate whole stack hw/sw to beckhoff But we would like to keep our keypad to control machine.

Keypad is connected via serial port.

Would it be possible to implement application That would interpret keys/commands from our keypad and translate them To execute action on Beckhoff controller ?

Please let me know how to start, which docs, files to download.
Obviously, this is high priority for us and I am responsible to Figure out wheter this will work.
Do you have any .net samples of interface applications ?
I am not concerned with that keypad part, rather than the part, where Beckhoff controller is being controlled by custom application

From what I understood we would need TwinCAT and some busterminal controllerr to controll servos. Twincat would do all the heavy lifting (PID axis controller, homing, Gcode job interpretation) and I would just need to implement module in PLC that would interpret keypad commands.
I could do that in .net (VB or C#)

Is that about right ? How much CNC router stuff is already implemented in TwinCAT?

thx

--G

Judging by some questions asked, I would strongly suggest contracting a professional automation company to do the conversion.

It is all possible. It is just a little bit too big of a project for someone with little previous experience.

I see. Any chance you could throw in some specific info?
Or general. What needs to be done.
Does whole firmware have to be reimplemented in PLC ?

In regards to the keypad, do you already have documentation for the serial interface to the keypad? If so, it should be fairly simple to communicate with it using the TwinCAT PLC Serial Communications library that is sold as an add-on to TwinCAT. That software is documented here...
http://infosys.beckhoff.com/content/1033/tcplclibserialcom/html/tcplclibsercom_concept.htm

Beckhoff's CNC controller is documented here...
http://infosys.beckhoff.com/content/1033/tccncoverview/html/overview.htm
I agree with LadderLogic, learning Beckhoff CNC is a major task and you should make sure you have adequate local support from an experienced source before you start.

SteveMaves: thx
that's (TwinCAT CNC) what I was looking for (I already came across serial module)
TwinCAT CNC seems to be what we want to make work on our machine
and then make it work with our keypad.
what would be good to make user interface to controll machine ?
ist there something that would enable to run basic CNC functions of TwinCat CNC ? (like homing, toolchange, job loading, surface setting, job execution)

thx

Hi gastan. TwinCAT has many different software options for programming the HMI software, I would defer that question to your local support, it could be VB, C#, etc, etc, depending on your expertise and the expertise of the people you are working with.

Beckhoff has many choices for hardware, including screens with buttons and jog wheels built in for CNC applications...
http://www.beckhoffautomation.com/english/industrial_pc/c9900_ex8x_cnc.htm?id=20384762077317

One disclaimer, I do work for Beckhoff in the USA.

SteveMaves: It's no biggie. My boss is sold on Beckhoff as of now.
We're based in Germany, so I suppose we would be dealing with German support then.
I want to get to know how the future system will/may look like.
If I figure it may be more viable to get somebody from Beckhoff down to our shop and set up our machine on their controller, I will suggest that to my boss.
From what I understand one can setup simulated axis on CNC, so maybe I could set up some virtual CNC machine and play with it a little bit.

gastan,

Re interface to your serial keypad, easiest is probably via your .net program. The response won't be real-time, and it is possible a Windows service or virus-scanner could cause delays. If you require real-time response, then consider a direct serial interface to the PLC code as SteveMaves suggests. A very simple system could be all PLC, with no Windows program if you don't need graphics for the operator.

You generally will use a Beckhoff PC as the "PLC brain" since they won't sell their run-time engine for other PC's (could run via full PLC-control, but expensive). You can run your Windows program directly on the PLC brain, which most people do. You can also run your Windows program on a separate PC that talks to the brain via ethernet, easy to configure either way. The interface from Windows to PLC code is simple and direct. You can read or write PLC variables (or arrays), start, stop, reset the PLC, etc. The Windows program has complete control.

RocketTester,

thank you very much. Your post was very informative.
Can you please point me to direction where I can see more detailed info about CNC module ?
Like detailed list of features. I am trying to figure how much we will be able to use of existing functionality and how much will need to be implemented as far as our special features go (surface compensation, plasma cutter, oscilating knife, barcode reader)

thx

gastan,

I have not used Beckhoff's CNC functions, but many people do. You will probably need the new, fast EtherCAT modules (E-bus) instead of the older "Bus Terminal" (K-bus), especially if you must keep 2 axes synchronized to generate a profile. Cost is similar, but some E-bus modules aren't yet available (website shows estimated release). You can actually mix the two types fairly easily with couplers.

SteveMaves link above is to a CNC operator's panel. The other part is software. You probably need the TwinCAT CNC add-on, which is extra cost. See
www.beckhoffautomation.com/english/twincat/twincat_cnc.htm?id=508051217

Re performance, view this video
www.beckhoffautomation.com/english/images/Video_Podcast_Webcast/2009/HMI/TwinCAT_Kinematic_Transformation/TwinCAT_Kinematic_Transformation_e.swf?scale=noscale

Besides the fast I/O, an interesting thing is that the kinematic equations are calculated on-the-fly in PLC code. The equations convert the desired x,y,z position and angular orientation of the stylus tip into the required angular positions of the rotary positioners. I have read that PLC code can be as fast as the best C code and this video demonstrates that. This means you can manage the direct cartesian coordinates and let the PLC figure out how to realize them, which should simplify configuration management.