| CANopen
SlaveLib
Developers wanted!
This is a preview version of the CANopen SlaveLib. It is yet useful for
very simple CANopen devices, but should become a complete standard
compliant CANopen library for slave devices. To get to this point, we
need more developers and testers! This is the right time for developers
to download this project and participate the development process. If
you're interested in developing this library, contact me: zulli@gmx.net and send me your
sourceforge username (if available) so i can add you to the developers
list.
About
CANopen SlaveLib is an opensource CANopen implementation for slave
Devices. Its license is LGPL.
The aim of this software
- Opensource and therefore available for everyone
- Standard-compliant
- Highly portable
- Programmed in ANSI-C (especially because of the
portability)
- ... lets find some other goals (such as
memory-optimized and
Project state
This library should be called developer release because not all
features of canopen are implemented at the moment. The features that
are implemented should be stable (at least there are no known problmes).
Implemented features an their limitations:
- The object dictionary (including accessing it)
is created. It supports communication parameters, such as
manufacturer information, serial number of the device, revision
number, ... It also supports error register entries (although they
are not used by the library), and so on. Heartbeat settings
(Heartbeat consumer/producer) can be placed into the object dictionary.
The heartbeat settings are used by the CANopen SlaveLib. Server/Client
SDO Parameter can be setted up too. This settings are not used by the
library at the moment. PDO communication and mapping Parameter can also
be setted up. They are used by the library (there are some
limitations: e.g. only transmission type 255 is supported yet).
Digital I/O-Profile (DS-401) are implemented (I don't know exactly
this standard, so at the moment there's only digital I/O implemented
(with support of 8Bit variables).
- PDO transfer should work quite well. The
CANopen SlaveLib should recognize incoming PDO-Messages, analyse
them, check wheter the node is a consumer of the arrived PDO and if
this is the case, it sets the local variable to the new value. Also
sending of PDOs should work well. If a process variable (a local one)
changes, the correct function has to be called manually. This function
sends the changed (even if there are more than one defined variable,
only the changed ones are sent: transmission type 255) values via
PDO-Message. Limitation: all this features only works for
transmission type 255 yet. Remotely requested PDO transfer does
also not work.
- Heartbeat is working: Heartbeat-messages are
sent in predefined times (the defined time is read from the object
dictionary). Incoming heartbeats are analysed and, if a heartbeat
hasn't arrived within the predefined time (this time is also
configured in the object dictionary) a function is called, where the
user can handle this event/error.
- With the CANopen SlaveLib you can start and
stop remote CANopen devices. There should be no limitations
- The CANopen SlaveLib comes with a state
machine, which works in the manner CANopen demands a state machine:
After power up of the device, the statemachine automatically starts
with the initialisation phase. After initialisation it automatically
changes into pre-operation state. It remains there until a
start-remote-node message arrives (normally sent by the master). then
it changes into the operation state. The device can then be stopped
or reseted. Limitations: Not all functions are allowed in all
states (e.g. sending/receiving of PDO shouldn't be possible in
pre-operational state). This restriction is not yet implemented, but
should be done within one or two hours.
- NMT-services are implemented. This lib contains
a state machine (initialisation of commnication and node,
pre-operational, operational, stopped). This states can be changed
by receiving NMT messages from a NMT master.
Not yet implemented features (to do list):
- SDO Transfer should be implemented, so other
nodes can access the object directory of devices programmed with
this CANopen SlaveLib. This shouln't be very tricky, since this
functionality can more or less be copied from the CanFestival
project (http://canfestival.sourceforge.net).
- Sync objects should be implemented, so the
SlaveLib can send Syncs and also receives/analyses sync-objects.
- Emergency-messages should be implemented, so it
is possible for devices to send internal errorstates. Implementing
this feature shouln't take too much time.
- Implement PDO transfer for the other
transmission types (as described above: only transmission type 255
is implemented at the moment)
- PDO transfer for remotely requested PDOs should
be implemented.
- More profiles should be implemented. Also a new
design for easily using/implementing different profiles should be
created. It should be very easy (for the user of this library) to
choose one or more profiles without knowing too much about CANopen.
- A memory optimized and a speed optimized
version should be created. This two versions should ideally consists
in the same sourcecode (maybe by preprocessor-directives the user can
tell the compiler which version he wants to use). I assume that for
example a Linux-CANopen slave must be speedoptimized, where a
personal computer comes with more than enough memory. On the other
side, microchip based CANopen slave has to be memory optimised,
because of its memory limitations.
- A (very) future step should be to create a GUI
application which helps the user to use this CANopen SlaveLib. I
imagine a GUI in which the user can manipulate all constants
graphically (e.g. how many receive/transmit PDO, how many heartbeats
he listens, ...) and also put his ''user-code'' (the application that
runs on the microchip) in, so the GUI automatically puts this
''user-code'' into the correct section (function) of the app.c file.
In short: in future, it should be possible to create CANopen devices,
without knowing much about CANopen.
- Together with the GUI we should create a
program which automatically creates (standard conform) EDS files.
- Porting the library to a wide range of
platforms/compilers.
Documentation The documentation for this library has
been written in LaTeX and can be downloaded as PDF and as sourcecode
form this homepage. The documentation has been splitted into two
pieces: a developer manual and a user manual. Additionally you can find
the API-documentation (generated with doxygen) on this homepage, or
you can download it for offline browsing. The text on this homepage is
(more or less) copied out of this two documents. For more detailed
information read this two documents.
Download this documents here:
Developing We are searching for developers! If you are
able and willing to implmement some of the missing features or wanna
test this library and find/correct bugs, please feel free to do! for
any questions contact: zulli@gmx.net
Downloads As described, CANopen SlaveLib is available
for two different platforms. Therefore, you can download two different
versions of the CANopen SlaveLib: one for Linux and one for Microchip's
PIC microcontroller. Download them here:
Installation Please download the PDF documentation
files for information about installation and usage.
Special thanks goes to:
- Edouard Tisserant (developer of CANFestival)
who helped me creating the object dictionary. Also some pieces of
code has been taken from his project (which is now LPGL too)
- Roland Rütimann who helped me solve
problems while programming the PIC microcontroller.
- HSR (Hochschule Rapperswil www.hsr.ch) where this project was born.
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