incubator-cvs mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Apache Wiki <>
Subject [Incubator Wiki] Update of "Plc4XProposal" by ChristoferDutz
Date Sat, 09 Dec 2017 22:00:31 GMT
Dear wiki user,

You have subscribed to a wiki page "Incubator Wiki" for change notification.

The page "Plc4XProposal" has been deleted by ChristoferDutz:

- = Abstract =
- PLC4X is intended to become a set of libraries for communicating with industrial programmable
logic controllers (PLCs) using a variety of protocols but with a shared API.
- For the most used of these protocols, PLC4X will provide implementations of drivers. Each
protocol driver is hereby provided by an individual artifact.
- In a first step, we are concentrating on Java but will be hoping to be able to port implementation
to C and other languages.
- = Background =
- Industrial machines have been controlled by PLCs for more than 30 years. In simpler pieces
of machinery these may operate autonomously, in more complex ones several to hundreds of these
industrial computers communicate with each other.
- = Rationale =
- Currently software for communicating with PLCs is mainly proprietary software and a whole
ecosystem of closed-source solutions exist. Usually this software is very expensive and licensing
implies a lot of restrictions on its usage. There is a small set of open-source libraries
available, but unfortunately most of these are GPL licensed and hereby disqualify themselves
from commercial use. Most of these are direct ports from C/C++ implementations and therefore
inherit their API. Usually these are implemented blocking socket operations and have great
problems with concurrency. Also, the APIs of these tools differ quite a lot, so porting a
software from communicating with one type of PLC to another sometimes requires re-writing
a great part of the software.
- There are multiple rationales behind this project:
-  1. By providing libraries with Apache license, it will be possible to create commercial
applications which access PLCs
-  2. By providing a universal API for different protocols, it reduces the vendor lock-in
when creating software
-  3. Most of the proprietary commercial solutions are based on Windows systems, especially
the Siemens solutions, sometimes require maintaining un-patched versions of older Windows
version in order to run, this is a huge security risk (See Stuxnet)
-  4. Most of the proprietary commercial solutions don't scale. Running them in public/private
clouds and/or in containers is completely out of the question.
- As a result of above, it would be possible to start writing secure, scalable and reliable
software using the full stack of open-source solutions and hereby open a complete new market
for developers. In order to make this even easier, we are planning on directly providing adapters
and examples for using PLC4X together with other Apache frameworks.
- = Initial Goals =
- Develop a universal API for accessing industrial programmable logic controllers in a protocol-agnostic
way. Also implement Java versions of drivers for the most prominent protocols: S7, Modbus
and OPC-UA - but not limited to those. On the side of the adapters, for existing OS solutions,
we are currently working on adapters for: Apache Edgent (incubating), Apache Camel and eventually
even Apache Brooklyn.
- Also, we will be providing a Scala wrapper to ease integration of PLC4X in Scala based systems
with an API Scala developers should easily adopt.
- As soon as a C version exists, we are planning on providing an Apache Mynewt adapter as
we see great benefits on this combination.
- = Current Status =
- == Meritocracy ==
- PLC4X was initially created by Christofer Dutz. He is an Apache Member and also involved
in a variety of Apache and Non-Apache Open-Source projects. Being PMC of the Apache Flex,
Apache Kibble and the Apache Travel Assistance he definitely knows how Apache works and is
a strong advocate of the Apache Way. He is also currently helping the Apache Edgent project
as member of the PPMC. However, the team working on PLC4X also includes a diverse set of additional
Apache Committers and Members as well as people, that are not yet affiliated with any Apache
project. The team working on PLC4X are both working for codecentric as well as other entities,
such as commercial companies as well as universities.
- == Community ==
- Currently the PLC4X community exists out of a set of core developers working on a private
code repository provided by codecentric (the company Christofer Dutz is working for). However,
the set of developers, working on PLC4X is not limited to codecentric employees as we are
also inviting outside contributors.
- The main reason for using a private repo instead of a public one, is that we were planning
on starting incubation at Apache within a few weeks after initiating the project. Therefore,
we wanted to start writing everything with Apache package names and Apache Maven coordinates.
Even our logo is directly designed including the Apache Feather and "Apache" inside the name.
As only real Apache projects are allowed to use "Apache", we decided to go down the private
repository path.
- == Core Developers ==
- (In alphabetical order)
-  * Benedikt Ritter (codecentric) (Apache Member)
-  * Christofer Dutz (codecentric) (Apache Member)
-  * Dale LaBossiere (IBM) (PPMC Member of the Apache Edgent incubator podling)
-  * Frank Stibane (codecentric)
-  * Greg Trasuk (Web Age Solutions) (Apache Member)
-  * Justin McLean (External) (Apache Member)
-  * Kai Herings (codecentric)
-  * Lukas Friedrichsen (Hochschule Bochum)
-  * Mark Keinhörster (codecentric)
-  * Rolf Felker (codecentric)
-  * Sebastian Rühl (codecentric)
- == Alignment ==
- The build system is based on Apache Maven. Also, it uses Apache Edgent (incubating) and
Apache Camel libraries for providing adapters to these systems. Being a full-blown Apache
enthusiast, for Christofer there hasn't been any thought in bringing this project into any
other collaboration platform or foundation. This idea is shared by a big majority of the core
- == Project Name ==
- As we know that renaming a codebase can be a huge pain, we have invested quite a lot of
time into finding a suitable name. In the end, we came up with a list of about 20 project
names, which we did the fully required background checks for. On the options surviving these
checks, we internally voted on the name. It was a pretty close tie between PLC4J and PLC4X,
but we decided to go for the later as we are planning on providing libraries for multiple
languages beyond Java.
- PLC4X has no registered trademarks that we could find and the only potential problem would
be a hardware LPT Breakout Board by a Russian Company called Purelogic (
English version (
- But we don't see any problems to arise from this. If there would be problems, we would probably
fallback to using PLC4J, which had no conflicts at all and would eventually name our sub-products
PLC4S (Scala) and PLC4C (C/C++).
- = Known Risks =
- == Orphaned projects ==
- PLC4X is a new Project, which has just been started. The feedback from the industry has
been overwhelming so the risk of the project being orphaned is minimal.
- == Inexperience with Open Source ==
- The set of core developers of this project consists of a large set of experienced open-source
developers, most of these even being Apache Members.
- == Homogeneous Developers ==
- Even if a big part of the projects initial committer team is affiliated with codecentric,
we have been successful and continuing to be in actively recruiting people from other commercial
and non-commercial entities.
- == Reliance on Salaried Developers ==
- Currently only Christofer Dutz is being paid to work on this project exclusively.
- == Relationships with Other Apache Products ==
- PLC4X makes great used of Apache Maven for the build system and Apache Commons for providing
a lot of basic functionality.
- Also does it currently have direct relations to the Apache Camel and Apache Edgent projects
as it provides modules for direct integration of PLC4X into these frameworks.
- In the future we are planning on also adding such modules for Apache Brooklyn and as soon
as a C-based version of PLC4X is available Apache Mynewt.
- Currently there is no competing project at the Apache Software Foundation.
- == An Excessive Fascination with the Apache Brand ==
- We are certain that PLC4X itself will profit from being an official Apache project, in terms
of attracting a community and establishing a solid group of developers and users, but also
to ease the interaction with other Apache projects, used in PLC4X or project PLC4X provides
adapters for as all will share the same base.
- Our general belief in the Apache way as well as the reasons mentioned above are the main
reasons for us to send this proposal. We think that a good community is needed to build and
maintain good software, such as PLC4X. Also do we need a big community to support a big variety
of systems. However, even if PLC4X would not be accepted, development would definitely continue
elsewhere. Apache is just our primary foundation of choice. As such, there is no need to,
or reason to, "abuse" the Apache Brand.
- == Possibility of legal actions ==
- Some of the protocols are not publicly defined. Existing open-source implementations contain
licensing restrictions. To avoid licensing issues we made sure the license of information
used to implement drivers in PLC4X are compatible with the Apache license and added references
to these sources in the project documentation to prove this. This documentation is part of
the codebase. We are therefore not expecting any real problems on this side.
- == Test setup could require hardware ==
- A test-suite for PLC4X could involve tests run against virtual or real hardware. It could
be problematic to include these in automated builds run on, but Apache infra
have already signaled that there should be options to work this out.
- = Documentation =
- Currently all documentation and information is stored alongside the code in a private corporate
GIT repository and is available as part of the website which is generated as part of the build.
- = Initial Source =
- Development of PLC4X started at codecentric in October of 2017. The source currently is
located on a private corporate GIT repository. All the code is available at
(Accounts can be created on a request basis)
- = Source and Intellectual Property Submission Plan =
- PLC4X is currently mainly developed by, but not limited to, codecentric employees. However,
all code has been developed completely from scratch it was ensured from the start that each
document is already fully licensed under the Apache 2.0 license. All source will be donated
to Apache without any exceptions.
- = External Dependencies =
-  * Apache Commons-IO, Apache License 2.0
-  * Apache Edgent, Apache License 2.0
-  * Netty, Apache License 2.0
-  * Metrics Core, Apache License 2.0
-  * Google Gson, Apache License 2.0
- This source can be included, according to
-  * Logback, EPL 1.0
- This source can NOT be included, according to
- = Cryptography =
- Not applicable.
- = Required Resources =
- == Mailing Lists ==
-  * plc4x-dev
-  * plc4x-private
- == Git Repository ==
- == Issue Tracking ==
- == Confluence Wiki ==
- To be able to provide help, documentation, faq etc, a wiki is needed.
- = Initial Committers =
- (In alphabetical order)
-  * Benedikt Ritter (
-  * Christofer Dutz (
-  * Dale LaBossiere (
-  * Frank Stibane (
-  * Greg Trasuk (
-  * Justin McLean (
-  * Kai Herings (
-  * Lukas Friedrichsen (
-  * Mark Keinhörster (
-  * Rolf Felker (
-  * Sebastian Rühl (
- = Affiliations =
- Currently most of the initial committers are employees of codecentric. Currently Christofer
Dutz is the only contributor paid to work on PLC4X full-time. The others participate as part
of their so-called "+1 time" (At codecentric employees get to spend 20% of their time to work
on open-source, education, etc. and they invest a lot of this time on the project).
- Besides these we also have contributors from companies other than codecentric (Dale, Greg,
Justin) as well as universities (Lukas).
- = Sponsors =
- == Champion ==
-  * Justin McLean
- == Nominated Mentors ==
- (In alphabetical order)
-  * Greg Trasuk
-  * Justin McLean
-  * Luciano Resende
-  * Stefan Bodewig
- == Sponsoring Entity ==
- PLC4X is a new project and proposed is to release to code under the sponsorship of the Incubator.

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message