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2. Computer

2.1. Minimum Requirements{Minimum Requirements}

The minimum system to run EMC2 and Ubuntu may vary depending on the exact usage. Stepper systems in general require faster threads to generate step pulses than servo systems. Using the Live-CD you can test the software before committing a computer. Keep in mind that the Latency Test numbers are more important than the processor speed for software step generation. More information on the Latency Test is in Section ([sub:Latency-Test]).

Additional information is on the EMC Wiki site:

http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Hardware_Requirements

EMC2 and Ubuntu should run reasonably well on a computer with the following minimum hardware specification. These numbers are not the absolute minimum but will give reasonable performance for most stepper systems.

  • 700 MHz x86 processor (1.2 GHz x86 processor recommended)
  • 384 MB of RAM (512 MB up to 1 GB recommended)
  • 4 GB hard disk
  • Graphics card capable of at least 800x600 resolution, which is not using the NVidia or ATI fglrx proprietary drivers, and which is not an onboard video chipset that shares main memory with the CPU
  • A network or Internet connection (not strictly needed, but very useful for updates and for communicating with the EMC community)

2.2. Problematic Hardware

2.2.1. Laptops

Laptops are not generally suited to real time software step generation. Again a Latency Test run for an extended time will give you the info you need to determine suitability.

2.2.2. Video Cards

If your installation pops up with 800 x 600 screen resolution then most likely Ubuntu does not recognize your video card or monitor. Onboard video many times causes bad real time performance.

2.3. About EMC

2.3.1. The Software

  • EMC (the Enhanced Machine Control) is a software system for computer control of machine tools such as milling machines and lathes.
  • EMC is free software with open source code. Current versions of EMC are entirely licensed under the GNU General Public License and Lesser GNU General Public License (GPL and LGPL)
  • EMC provides:
  • a graphical user interface (actually several interfaces to chose from)
  • an interpreter for G-code(the RS-274 machine tool programming language)
  • a realtime motion planning system with look-ahead
  • operation of low-level machine electronics such as sensors and motor drives
  • an easy to use breadboardlayer for quickly creating a unique configuration for your machine
  • a software PLC programmable with ladder diagrams
  • easy installation with a Live-CD
  • It does not provide drawing (CAD - Computer Aided Design) or G-code generation from the drawing (CAM - Computer Automated Manufacturing) functions.
  • It can simultaneously move up to 9 axes and supports a variety of interfaces.
  • The control can operate true servos (analog or PWM) with the feedback loop closed by the EMC software at the computer, or open loop with step-servosor stepper motors.
  • Motion control features include: cutter radius and length compensation, path deviation limited to a specified tolerance, lathe threading, synchronized axis motion, adaptive feedrate, operator feed override, and constant velocity control.
  • Support for non-Cartesian motion systems is provided via custom kinematics modules. Available architectures include hexapods (Stewart platforms and similar concepts) and systems with rotary joints to provide motion such as PUMA or SCARA robots.
  • EMC runs on Linux using real time extensions.

2.3.2. The Operating System

Ubuntu has been chosen, because it fits perfectly into the Open Source views of EMC2:

  • Ubuntu will always be free of charge, and there is no extra fee for the enterprise edition, we make our very best work available to everyone on the same Free terms.
  • EMC is paired with the LTS versions of Ubuntu which provide support and security fixes from the Ubuntu team for 3 - 5 years.
  • Ubuntu uses the very best in translations and accessibility infrastructure that the Free Software community has to offer, to make Ubuntu usable for as many people as possible.
  • The Ubuntu community is entirely committed to the principles of free software development; we encourage people to use open source software, improve it and pass it on.

2.4. Getting Help

2.4.1. IRC

IRC stands for Internet Relay Chat. It is a live connection to other EMC users. The EMC IRC channel is #emc on freenode.

The simplest way to get on the IRC is to use the embedded java client on this page http://www.linuxcnc.org/content/view/4/8/lang,en/.

Some IRC etiquette:

  • Ask specific questions… Avoid Can someone help me?, It won’t runtype of questions.
  • If you’re really new to all this, think a bit about your question before typing it. Make sure you give enough information so someone can solve your question.
  • Have some patience when waiting for an answer, sometimes it takes a while to formulate an answer or everyone might be busy working or something.
  • Set up your IRC account with your unique name so people will know who you are. If you use the java client, use the same name every time you log in. This helps people remember who you are and if you have been on before many will remember the past discussions which saves time on both ends.
2.4.1.1. Sharing Files

The most common way to share files on the IRC is to upload the file to one of the following or a similar service and paste the link:

http://pastebin.ca = for text
http://imagebin.ca = for pictures
http://filebin.ca = for files and pdfs

2.4.2. Mailing List

An Internet Mailing List is a way to put questions out for everyone on that list to see and answer at their convenience. You get better exposure to your questions on a mailing list than on the IRC but answers take longer. In a nutshell you e-mail a message to the list and either get daily digests or individual replies back depending on how you set up your account.

Information about the EMC Users Mailing List at:

https://lists.sourceforge.net/lists/listinfo/emc-users

2.4.3. EMC Wiki

A Wiki site is a user maintained web site that anyone can add to or edit.

The user maintained EMC Wiki site contains a wealth of information and tips at:

http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl

2.5. Get EMC2

2.5.1. Normal Download

Download the Live CD from:

http://www.linuxcnc.org/

and follow the Download link.

2.5.2. Multi-session Download{Multi-session Download}

If the file is too large to download in one session because of a resuming downloads.

2.5.2.1. Wget Linux{Wget Linux}

Open a terminal window. In Ubuntu it is Applications/Accessories/Terminal. Note that actual file names may change so you might have to go to http://www.linuxcnc.org/ and follow the Download link to get the actual file name. In most browsers you can right click on the link and select Copy Link Location or similar then paste the link into the terminal window with a right mouse click and select Paste.

To get the Ubuntu 8.04 Hardy Heron version copy this in the terminal window and press enter:

{textbf{wget -r http://www.linuxcnc.org/hardy/ubuntu-8.04-desktop-emc2-aj07-i386.iso}To} get the Ubuntu 6.06 Dapper Drake version:

{textbf{wget -r http://www.linuxcnc.org/iso/emc2.2.2-1-ubuntu6.06-desktop-i386.iso}To} continue a download that has been stopped add the -c option to wget:

{textbf{wget -r -c http://www.linuxcnc.org/hardy/ubuntu-8.04-desktop-emc2-aj07-i386.iso}To} stop a download use Ctrl-C or close the terminal window.

After the download is complete you will find a new directory called www.linuxcnc.org or something similar. In the subdirectory under the above directory you will find the ISO CD image file. Next is burning the CD.

2.5.2.2. Wget Windows{Wget Windows}

The wget program is also available for Windows from

http://gnuwin32.sourceforge.net/packages/wget.htm

Follow the instructions on the web page for downloading and installing the windows version of the wget program.

To run wget open a command prompt window.

In most Windows it is Programs/Accessories/Command Prompt

First you have to change to the directory where wget is installed in.

Typically it is in C:\\Program Files\\GnuWin32\\bin so in the Command Prompt window type:

{textbf{cd C:\\textbackslashProgram Files\\textbackslashGnuWin32\\textbackslashbin}}and the prompt should change to C:\\Program Files\\GnuWin32>

Type the wget command into the window and press enter as above.

2.5.3. Burning the CD

EMC2 is distributed as CD image files, called ISOs. To install EMC2, you first need to burn the ISO file onto a CD. You need a working CD/DVD burner and an 80 minute (700 Mb) CD for this. If the CD writing fails, try writing at a slower burn speed.

2.5.3.1. Burn with Linux

Before burning a CD, it is highly recommended that you verify the md5 sum (hash) of the .iso file.

Open a terminal window. In Ubuntu it is Applications/Accessories/Terminal.

Change to the directory where the ISO was downloaded to.

{textbf{cd download\\\_directory}}The run the md5sum command with the file name you saved.

{textbf{md5sum ubuntu-8.04-desktop-emc2-aj07-i386.iso}}The md5sum should print out a single line after calculating the hash. On slower computers this might take a minute or two.

{textbf{91c5abb84386091e0ff056e9ebc40fdb ubuntu-8.04-desktop-emc2-aj07-i386.iso}}Now compare it to the md5sum on the EMC2 download page.

Burning the ISO to a CD

  1. Insert a blank CD into your burner. A CD/DVD Creatoror Choose Disc Typewindow will pop up. Close this, as we will not be using it.
  2. Browse to the downloaded ISO image in the file browser.
  3. Right click on the ISO image file and choose Write to Disc.
  4. Select the write speed. If you are burning a Ubuntu Live CD, it is recommended that you write at the lowest possible speed.
  5. Start the burning process.
  6. If a choose a file name for the disc image window pops up just pick OK.
2.5.3.2. Burn with Windows

Before burning a CD, it is highly recommended that you verify the md5 sum (hash) of the .iso file.

Windows does not come with a md5sum program. You will have to download and install one to check the md5sum. More information can be found at:

https://help.ubuntu.com/community/HowToMD5SUM

Burning the ISO to a CD

  1. Download and install Infra Recorder, a free and open source image burning program.
  2. Insert a blank CD in the drive and select Do nothing or Cancel if an auto-run dialog pops up.
  3. Open Infra Recorder, and select the Actions menu, then Burn image.

2.5.4. Testing EMC2

With the Live CD in the CD/DVD drive shut down the computer then turn the computer back on. This will boot the computer from the Live CD. Once the computer has booted up you can try out EMC2 without installing it. You can not create custom configurations or modify most system settings like screen resolution unless you install EMC2.

To try out EMC2 from the Applications/CNC menu pick EMC2. Then select a sim configuration to try out.

To see if your computer is suitable for software step pulse generation run the Latency Test as outlined in Section ([sub:Latency-Test])

2.5.5. Installing EMC2

If you like what you see, just click the Install icon on the desktop, answer a few questions (your name, timezone, password) and the install completes in a few minutes. Make sure you write down the name you used and the password. Once the install process is complete and you go on line the update manager will pop up and allow you to upgrade to the latest stable version of EMC2.

2.5.6. Axis Interface

The AXIS interface is one of the interfaces to choose from. It can be configured to add a Virtual Control Panel to customize the interface to suit your needs. AXIS is the default user interface and is actively being developed.

.

2.5.7. Updates to EMC2{Updates to EMC2}

With the normal install the Update Manager will notify you of updates to EMC2 when you go on line and allow you to easily upgrade with no Linux knowledge needed. If you want to upgrade to 10.04 from 8.04 a clean install from the Live-CD is needed. It is OK to upgrade EMC when asked to.

Warning: Do not upgrade Ubuntu to a new version (like 8.04 to 8.10) as it will prevent EMC from running.

2.5.8. Install Problems

In rare cases you might have to reset the BIOS to default settings if during the Live CD install it can not recognize the hard drive during the boot up.

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