3.0.2

libmodbus

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• Fork me, I’m famous! on 2012-02-06

  The modbus library finds its way into the official repositories Fedora (packaged by Stéphane Raimbault), Debian and Ubuntu (packaged by Ivo De Decker).

  https://community.dev.fedoraproject.org/packages/libmodbus
  http://packages.debian.org/search?keywords=libmodbus
  http://packages.ubuntu.com/search?keywords=libmodbus

  Of course, we'll happy to support other distributions!

  To improve the communication and ease the subscription process, the libmodbus project as moved from Launchpad list to Google Groups libmodbus@googlegroups.com.

  Update: Julien Boibessot integrated libmodbus into Buildroot.

• libmodbus v3.0.2 on 2012-02-06

  Yet another stable release with minor fixes.

  libmodbus 3.0.2 (2012-01-16)

  • Update Debian package.
  • Documentation fixes and additions.
  • Add missing C++ macros in public headers. Thanks to Bernhard Agthe.
  • Protects modbus_mapping_free against NULL argument. Thanks to Andrea Mattia.
  • Fix check on file doc/libmodbus.7 in acinclude.m4 (closes #28)
  • Close file descriptor when the settings don't apply in RTU. Original patch provided by Thomas Stalder.
  • unit-test.h is now generated to avoid config.h dependency.
  • Request for Windows Sockets specification version 2.2 instead of 2.0. Thanks to Pavel Mazniker for the report.

• v3.0.1 to avoid ".0" problems on 2011-07-22

  A dot zero isn't a dot zero without few problems, so I've released libmodbus v3.0.1 to fix problems with non-recent Linux kernels and other platforms.

  libmodbus 3.0.1 (2011-07-18)

  • Avoid useless serial_mode integer when TIOCSRS485 isn't supported
  • Fix compilation failure on Windows (RS485 support) by Tobias Doerffel
  • Properly check TIOCSRS485 define by Matthijs Kool
  • Rename package to libmodbus5 to fix lintian warning

• Magic libmodbus 3.0.0 is out on 2011-07-12

  OK, the new stable release of libmodbus is finally out! Only 2 years after libmodbus v2.0.3 and 400 commits, I'm happy to release this new version which contains many changes to improve the API and enhance the Modbus protocol conformity. The major features of this release are:

  • more coherent and extended API
  • POSIX error return codes
  • full documentation of the API
  • IPv6 support
  • new backend design
  • support for Windows, MacOS X and FreeBSD
  • rewriting of the message reading to avoid timeout
  • native serial communication on Windows

  Thanks to the many contributors

  Tobias Doerffel, Florian octo Forster, Hannu Vuolasaho, Patsy Kaye, Ivo De Decker,
  Allan Cornet, Manfred Gruber, Jason Oster, Petr Parýzek, Antti Manninen, Barry Grumbine,
  Kirill Smelkov, Anibal Limón, David Olivari, Sisyph, aladdinwu, Jeff Laughlin, Yishin Li , Henrik Munktell, Paul Fertser, Norbert Koch and Stéphane Raimbault.

  The development continues for the next v3.1 release with this roadmap.

  Have fun!

• libmodbus v2.9.4 is out! on 2011-06-05

  This minor release contains many new features with IPv6 support, documentation (man and HTML), error recovery modes and small API changes. I'm intend to release the version 3.0 so I need feeback from this release even more if you use libmodbus on Windows or MacOS X (check nanosleep support for example).

  It's easy to test the library, just compile and run the unit tests! Don't forget to notify your success or failure (by mail, wiki or bug report), see the Call for Testers page or the mailing list for details.

  There are already Debian and Fedora packages but I need help to submit them to the distributions, so all experience in this field is appreciated.

  libmodbus 2.9.4 (2011-06-05)

  • IPv6 support  Make the TCP implementation "protocol independent" by Florian Forster  and Stéphane Raimbault.
  • Fix compilation on Windows 7 (x64) with MinGW/MSYS and GCC 4.
    Reported by Patsy Kaye.
  • Documentation of libmodbus functions with AsciiDoc (man and HTML) by Stéphane  Raimbault
  • Avoid an iteration in flush function
  • New functions to send and receive raw requests (modbus_send_raw_request,  modbus_receive_confirmation)
  • Fix flush function of TCP backend on Windows
  • API changes for server/slave:
    * modbus_receive doesn't take socket/fd argument anymore
    * new function modbus_set_socket to set socket/fd
  • API changes for timeout functions:
    * modbus_get_timeout_begin -> modbus_get_response_timeout
    * modbus_set_timeout_begin -> modbus_set_response_timeout
    * modbus_get_timeout_end -> modbus_get_byte_timeout
    * modbus_set_timeout_end -> modbus_set_byte_timeout
  • Fix longstanding limitation of server to wait forever
  • New functions modbus_set/get_serial_mode by Manfred Gruber and Stéphane  Raimbault for RS485 communications
  • Improved recovery mode (see modbus_set_error_recovery documentation) for  data link and protocol errors.
  • Fix compilation issue with Microsoft Visual Studio 2008.  Reported by Allan Cornet.

• Not compliant device can be time consuming! on 2011-04-27

  Travis Atkinson of Com-Pac Filtration and me have worked together to find out why the HMI of Weintek Labs I-Series, with Ethernet, answered only to request sent by the modpoll program (proprietary software).

  After many emails and the help of Wireshark, we have discovered modpoll uses the unit identifier as slave ID for TCP requests, according to the Modbus specs that's incorrect (cf page 23 of Modbus Messaging Implementation Guide v1.0b) but else the device drops the request! Two problems can sometimes lead to proper operation or Weintek company has designed this product on modpoll requests :-/

  PS: The workaround was to set the slave ID with modbus_set_slave()

• libmodbus for Arduino (almost!) on 2011-04-14

  The libmodbus project is a real success on many platforms and to conquer the world, I've written a version dedicated to Arduino devices. My goals are:

  • to talk with a standard Arduino UNO or Duemilanove via the integrated USB
    serial line (8N1)
  • to have the lowest footprint (binary sketch size and SRAM)
  • to be robust

  OK, you're right, other projects exist already:

  • Master/slave by jpmzometa and others is great but the reading in loop doesn't handle serial latency and the code contains too many arrays IMHO
  • ModbusMaster is a master and I want a slave.
  • Arduino-Modbus, the code is, eh, ugly!
  • modbusmq by Mario Di Bacco is based on libmodbus but it aims Modbus TCP.

  So I've extracted/adapted only the slave, RTU, reading/writing registers of libmodbus. To reduce the footprint even further, I've replaced the fast CRC code based on precomputed arrays (512 bytes) by a slow one (not so slow!). The result is clean library for Arduino able to handle exceptions if an error occurs.

  The binary sketch size is 2,450 bytes and around 1,830 bytes of memory still free when running on 2K SRAM model.

  The source code is available on github and have the project is referenced in the arduino.cc playground wiki.

• New IRC channel on 2011-04-06

  I've just registered #libmodbus channel on Freenode, so let's talk!

• The libmodbus documentation has landed on 2011-03-25

  You've been numerous to ask for documentation and the work of gass with GTK-doc help me to prioritize it, so this month I've finally tackled this problem but not as expected!

  At first, I loved the GTK-doc solution, I'm a GNOME lover after all, but GTK-doc can't generate man pages and the setup code is too cumbersome IMHO. To choose the best solution for libmodbus, I read a comparison matrix on Wikipedia, after some tests with GTK-doc, Doxygen and AsciiDoc, and I finally choose AsciiDoc.

  However, there is a major difference between AsciiDoc and the other envisaged solutions, the documentation isn't included in the source code. I used to think it was good idea to keep the both at the same place to keep them in sync but:

  • it doesn't prevent you to code without updating the documentation
  • the documentation must be escaped by the language comment tags
  • I don't want to abuse my wheel mouse (to skip documentation) when I code

  The 0MQ project, endless source of inspiration, was a very good starting point to learn some tricks with AsciiDoc.

  Now, I'm looking for help to review and extend the documentation which has just landed in git (make doc to generate man pages). I've generated the documentation in HTML for the web site.

• libmodbus v2.9.3 is out! on 2011-01-16

  During this development cycle, I've received more feedback than for any other releases. That's really cool, thank you! With this new release, you can consider to migrate from the previous 2.0.x series for your applications.

  libmodbus v2.9.3 (2011-01-14)

  • Major rewriting of the message reading (no more timeouts on exception)
  • New function to reply to an indication with an exception message modbus_reply_exception()
  • New function modbus_get_header_length(modbus_t *ctx)
  • New functions to manipulate data:
    • MODBUS_GET_INT32_FROM_INT16
    • MODBUS_GET_INT16_FROM_INT8
    • MODBUS_SET_INT16_TO_INT8
  • Fix GH-2. Read/write were swapped in _FC_READ_AND_WRITE_REGISTERS
  • Install an ignore handler for SIGPIPE on *BSD.
    Original patch by Jason Oster.
  • Fix closing of Win32 socket.
    Reported by Petr Parýzek.
  • Fix unit identifier not copied by the TCP server.
    Reported by Antti Manninen
  • Fix missing modbus_flush() in unit tests.
  • Fixes for OpenBSD by Barry Grumbine and Jason Oster

  This time, the release is not only availabe as tarball but also as Fedora and Ubuntu packages on the download page.

  For the next release, I've already merged my ipv6 branch (based on the work of Florian Forster), the rtai branch of Chris Cole is waiting for review (ah, RTAI, like in the good old days and I hope to take care of the gtk-doc work done by Luis Matos.