1. LinuxCNC Overview
DMP Electronics INC

2. Simple LinuxCNC Controlled Machine
2

3. OutLine





About the LinuxCNC
Linux / RTAI
LinuxCNC software
LinuxCNC Hierarchical
Configuring LinuxCNC
3

4. About the LinuxCNC



LinuxCNC is a descendent of the original
NIST(The National Institutes of Standards
and Technology) Enhanced Machine
Controller software.
LinuxCNC is precompiled with Ubuntu LTS
(long term support) versions for ease of
installation and longevity.
LinuxCNC runs on Linux using real time
extensions.
4

5. Linux / RTAI
User Space
5

6. LinuxCNC software

System Requirements





700 MHz x86 processor (1.2 GHz x86
processor recommended).
384 MB of RAM (512 MB up to 1 GB
recommended).
8 GB hard disk.
Graphics card capable of at least 1024x768
resolution.
A network or Internet connection (not strictly
needed, but very useful for updates and for
communicating with the LinuxCNC community).
6

7. LinuxCNC software

LinuxCNC provides:







a graphical user interface (actually several
interfaces to choose 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 breadboard layer for quickly creating
a unique configuration for your machine.
a software PLC programmable with ladder diagrams
easy installation with a Live-CD.
7

8. LinuxCNC - Axis GUI
8

9. LinuxCNC Hierarchical

Four main components to the LinuxCNC
software:





a motion controller (EMCMOT)
a discrete IO controller (EMCIO)
a task executor which coordinates them
(EMCTASK)
and one of several graphical user interfaces
In addition there is a layer called HAL
(Hardware Abstraction Layer) which
allows configuration of LinuxCNC without
the need of recompiling.
9

10. GUI
NML
EMCTASK
RS274 (G code)
SEQUENCING
INTERPRETER
LOGIC
NML
Share memory
Real time
EMCMOT
EMCIO
HAL pins
HAL pins
Hardware Abstraction Layer (HAL)
HAL pins
HAL pins
Real-time HWD
Non-Real-time HWD
10

11. LinuxCNC Hierarchical

EMCTASK
基於EMC2的數控系統軟件架構及通信機制分析(2010)
11

12. LinuxCNC Hierarchical

EMCMOT
12

13. LinuxCNC Hierarchical

EMCIO

Be used to control
some machine
actions like lube,
coolant, and
spindle direction
and speed
13

14. Configuring LinuxCNC





INI : The ini file overrides defaults that are
compiled into the LinuxCNC code.
HAL : The HAL files start up process modules and
provide linkages between LinuxCNC signals and
specific hardware pins.
VAR : The var file is a way for the interpreter to
save some values from one run to the next. These
values are saved from one run to another but not
always saved immediately.
TBL : The tbl file saves tool information.
NML : The nml file configures the communication
channels used by the LinuxCNC. It is normally
setup to run all of the communication within a
single computer but can be modified to
communicate between several computers.
14

15. Configuring LinuxCNC

The INI File Components




Comments
Sections
Variables
Custom Sections and Variables
Sections
Comments
Variables
15

16. Configuring LinuxCNC

Sections











[EMC] general information
[DISPLAY] settings related to the graphical user interface
[FILTER] settings input filter programs
[RS274NGC] settings used by the g-code interpreter
[EMCMOT] settings used by the real time motion
controller
[TASK] settings used by the task controller
[HAL] specifies .hal files
[HALUI] MDI commands used by HALUI
[TRAJ] additional settings used by the real time motion
controller
[AXIS_n] individual axis variables
[EMCIO] settings used by the I/O Controller
Example
16

17. Configuring LinuxCNC

Hardware Abstraction Layer (HAL)








Component
Parameter
Pin
Physical_Pin
Signal
Type
Function
Thread
17

18. Configuring LinuxCNC

Hardware Abstraction Layer (HAL)


Component
 A HAL component is a piece of software with
well-defined inputs, outputs, and behavior,
that can be installed and interconnected as
needed.
Parameter
 Many hardware components have adjustments
that are not connected to any other
components but still need to be accessed.
There are two types of parameters: input &
Output
18

19. Configuring LinuxCNC

Hardware Abstraction Layer (HAL)


Pin
 Hardware components have terminals which
are used to interconnect them. The HAL
equivalent is a pin or HAL pin. HAL pins are
software entities that exist only inside the
computer.
Physical_Pin
 Many I/O devices have real physical pins or
terminals that connect to external hardware.
To avoid confusion, these are referred to as
physical pins. These are the things that stick
out into the real world.
19

20. Configuring LinuxCNC

Hardware Abstraction Layer (HAL)

Signal


In a physical machine, the terminals of real
hardware components are interconnected by wires.
Type
 Bit - a single TRUE/FALSE or ON/OFF value




float - a 64 bit floating point value, with
approximately 53 bits of resolution and over 1000
bits of dynamic range.
u32 - a 32 bit unsigned integer, legal values are 0
to 4,294,967,295
s32 - a 32 bit signed integer, legal values are 2,147,483,647 to +2,147,483,647
Both pins and signals have types, and signals can
only be connected to pins of the same type
20

21. Configuring LinuxCNC

Hardware Abstraction Layer (HAL)


Function
 Each function is a block of code that performs
a specific action. The system integrator can
use threads to schedule a series of functions
to be executed in a particular order and at
specific time intervals.
Thread
 A thread is a list of functions that runs at
specific intervals as part of a realtime task.
When a thread is first created, it has a specific
time interval (period), but no functions.
Functions can be added to the thread, and will
be executed in order every time the thread
runs.
21

22. Configuring LinuxCNC
22

23. Configuring LinuxCNC

HAL Commands

loadrt

The command loadrt loads a real time HAL
component. Real time component
functions need to be added to a thread to
be updated at the rate of the thread
23

24. Configuring LinuxCNC

HAL Commands

addf

The command addf adds a real time
component function to a thread. You have
to add a function from a HAL real time
component to a thread to get the function
to update at the rate of the thread.
24

25. Configuring LinuxCNC

HAL Commands

loadusr

The command loadusr loads a user space
HAL component. User space programs are
their own separate processes, which
optionally talk to other HAL components
via pins and parameters. You cannot load
real time components into user space.
25

26. Configuring LinuxCNC

HAL Commands

net

The command net creates
a connection between a signal and and
one or more pins. If the signal does not
exist net creates the new signal.
26

27. Configuring LinuxCNC

HAL Commands

setp

The command setp sets the value of a pin
or parameter. The valid values will
depend on the type of the pin or
parameter.
27

28. Configuring LinuxCNC

HAL Commands

unlinkp

The command unlinkp unlinks a pin from
the connected signal. If no signal was
connected to the pin prior running the
command, nothing happens.
28

29. Configuring LinuxCNC

Example :


core_stepper.hal
standard_pinout.hal
29

30. Appendix

Parallel Port Driver

installing


Pins




loadrt hal_parport cfg="<config-string>"
parport.<p>.pin-<n>-out (bit) Drives a physical output pin.
parport.<p>.pin-<n>-in (bit) Tracks a physical input pin.
parport.<p>.pin-<n>-in-not (bit)Tracks a physical input pin,
but inverted.
Parameters



parport.<p>.pin-<n>-out-invert (bit) Inverts an output pin.
parport.<p>.pin-<n>-out-reset (bit) (only for out pins) TRUE
if this pin should be reset when the -reset function is executed.
parport.<p>.reset-time' (U32) The time (in nanoseconds)
between a pin is set by write and reset by the reset function if
it is enabled.
30

31. Appendix

Parallel Port Driver

Functions





parport.<p>.read (funct) Reads physical input pins
of port <portnum> and updates HAL -in and -innot pins.
parport.read-all (funct) Reads physical input pins of
all ports and updates HAL -in and -in-not pins.
parport.<p>.write (funct) Reads HAL -out pins of
port <p> and updates that port’s physical output
pins.
parport.write-all (funct) Reads HAL -out pins of all
ports and updates all physical output pins.
parport.<p>.reset (funct) Waits until reset-time has
elapsed since the associated write, then resets pins
to values indicated by -out-invert and -outinvert settings.
31

32. Appendix

software step pulse generation

installing


loadrt stepgen step_type=type0[,type1...]
[ctrl_type=type0[,type1...]] [user_step_type=#,#...]
FUNCTIONS



stepgen.make-pulses (no floating-point)
Generates the step pulses, using information computed
by update-freq. Must be called as frequently as possible, to
maximize the attainable step rate and minimize jitter.
Operates on all channels at once.
stepgen.capture-position (uses floating point)
Captures position feedback value from the high speed code
and makes it available on a pin for use elsewhere in the
system. Operates on all channels at once.
stepgen.update-freq (uses floating point)
Accepts a velocity or position command and converts it into a
form usable by make-pulses for step generation. Operates
on all channels at once.
32

33. Appendix

software step pulse generation

PINS







stepgen.N.counts s32 out
The current position, in counts, for channel N. Updated by captureposition.
stepgen.N.position-fb float out
The current position, in length units (see parameter position-scale).
Updated by capture-position.
stepgen.N.enable bit in
Enables output steps - when false, no steps are generated.
stepgen.N.velocity-cmd float in (velocity mode only)
Commanded velocity, in length units per second (see
parameter position-scale).
stepgen.N.position-cmd float in (position mode only)
Commanded position, in length units (see parameter position-scale).
stepgen.N.step bit out
Step pulse output.
stepgen.N.dir bit out
Direction output: low for forward, high for reverse.
33

34. Appendix

software step pulse generation

PARAMETERS

stepgen.N.frequency float ro
The current step rate, in steps per second, for channel N.

stepgen.N.maxaccel float rw
The acceleration/deceleration limit, in length units per second squared.

stepgen.N.maxvel float rw
The maximum allowable velocity, in length units per second. If the requested maximum
velocity cannot be reached with the current combination of scaling andmake-pulses thread
period, it will be reset to the highest attainable value.

stepgen.N.position-scale float rw
The scaling for position feedback, position command, and velocity command, in steps per
length unit.

stepgen.N.rawcounts s32 ro
The position in counts, as updated by make-pulses. (Note: this is updated more frequently
than the counts pin.)

stepgen.N.steplen u32 rw
The length of the step pulses, in nanoseconds. Measured from rising edge to falling edge.

stepgen.N.stepspace u32 rw
The minimum space between step pulses, in nanoseconds. Measured from falling edge to
rising edge.

stepgen.N.dirsetup u32 rw
The minimum setup time from direction to step, in nanoseconds periods. Measured from
change of direction to rising edge of step.

stepgen.N.dirhold u32 rw
The minimum hold time of direction after step, in nanoseconds. Measured from falling edge
of step to change of direction.
34

35. Installing LinuxCNC
DMP Electronics INC
35

36. LinuxCNC

Installing Ubuntu and LinuxCNC
from the LinuxCNC Live-CD


Ubuntu 8.04 "Hardy Heron" LTS
Ubuntu 10.04 "Lucid Lynx" LTS
36

37. Download

http://www.linuxcnc.org/index.php/english/downl
oad
37

38. LinuxCNC
38

39. LinuxCNC Start
39

40. Stepping Start
40

41. Install build-dev

http://www.linuxcnc.org/hardy/dists/hardy/linuxcnc
2.5/source/linuxcnc_2.5.3.dsc
41

42. Install build-dev & Git
42

43. Get Source
存放的目的地
43

44. Building LinuxCNC
44

45. Building LinuxCNC
45

46. Building LinuxCNC
46

47. Building LinuxCNC
47

48. Building LinuxCNC
48

49. Building LinuxCNC
49

50. LinuxCNC
50

51. LinuxCNC
51

52. LinuxCNC
Python Virtual Control Panel
52

53. 53

54. 54

55. 55

56. 56

57. 57

58. 58

59. PyVCP



Python based virtual control panel
Can be added to the Axis GUI
Be stand alone.
59

60. PyVCP


Customize interface
Test or monitor
60

61. Panel Construction


Specify with an XML file
Widget tags are placed between
<pyvcp> and </pyvcp>
61

62. Panel Construction


Connect HAL signals to and from the
PyVCP pins
Example
62

63. AXIS
1.
2.
3.
4.
Create an .xml file that contains your
panel description and put it in your
config directory.
Add the PyVCP entry to the [DISPLAY]
section of the ini file with your .xml file
name.
Add the POSTGUI_HALFILE entry to the
[HAL] section of the ini file with the
name of your postgui HAL file name.
Add the links to HAL pins for your panel
in the postgui.hal file to connect your
PyVCP panel to LinuxCNC
63

64. AXIS
64

65. AXIS

Create an .xml
65

66. AXIS

[DISPLAY] section (.ini file)


[HAL] section (.ini file)


PYVCP = spindle.xml
POSTGUI_HALFILE =
spindle_to_pyvcp.hal
links to HAL pins (.hal file)

net spindle-rpm-filtered =>
pyvcp.spindle-speed
66

67. Stand Alone
1.
2.
3.
Create an .xml file that contains
your panel description and put it in
your config directory
Add a loadusr line to your .hal file
to load each panel.
Add the links to HAL pins for your
panel in the postgui.hal file
to connect your PyVCP panel to
LinuxCNC.
67

68. Stand Alone

load a stand alone PyVCP panel


loadusr -Wn mypanel pyvcp -g WxH+X+Y -c
mypanel <path/>panel_file.xml
 -Wn panelname
 pyvcp < -g> < -c> panel.xml
 -g <WxH><+X+Y>
 -c panelname
Example


loadusr -Wn mypanel pyvcp -g
250x500+800+0 -c mypanel mypanel.xml
loadusr pyvcp mypanel.xml
68

69. Widgets


Bits are off/on signals
Numbers can be float, s32 or u32
1.
2.
3.
4.
5.
indicate bit signals: led, rectled
control bit signals: button, checkbutton,
radiobutton
indicate number signals: number, s32, u32,
bar, meter
control number signals: spinbox, scale,
jogwheel
Helper widgets: hbox, vbox, table, label,
labelframe
69

70. Widgets -- General Notes

tag-based and attribute-based
syntax



<led halpin="my-led"/>
<led>
<halpin>"my-led"</halpin>
</led>
Comments

<!-- My Comment -->
70

71. Widgets

Label

<label>
<text>"This is a Label:"</text>
<font>("Helvetica",20)</font>
</label>
71

72. Widgets

LEDs (bit)

Round LED

Rectangle LED
72

73. Widgets

Buttons (bit)

Text Button

Checkbutton
73

74. Widgets

Buttons (bit)

Radiobutton
74

75. Widgets

Number Displays (number)

Number

s32 Number / u32 Number
75

76. Widgets

Number Displays (number)

Bar

Meter
76

77. Widgets

Number Inputs (number)

Spinbox

Dial
77

78. Widgets

Number Inputs (number)

Scale
78

79. Widgets

Number Inputs (number)

Jogwheel
79

80. Widgets

Images

Image Bit

Image u32
80

81. Widgets

Containers

Borders
81

82. Widgets

Containers

Hbox

Vbox
82

83. Widgets

Containers

Table
83

84. Widgets

Containers

Tabs
84

85. Widgets

Containers

Labelframe
85

86. Example

With AXIS interface
86

87. Example – Jog Buttons

custompanel.xml file
87

88. Example – Jog Buttons

custom_postgui.hal file
88

89. Example -- Port Tester

ptest.xml file
89

90. Example -- Port Tester


ptest.hal file
To run the HAL file we use the following
command from a terminal window.

halrun -I -f ptest.hal
90

91. Thanks.
91