Hmm ... I usually always hit reply ... but I have seen some times the email
just goes to the sender ... strange ...
This time it didn't ...
Am 11.09.20, 09:30 schrieb "Julian Feinauer" <j.feina...@pragmaticminds.de>:
Forwarding it tot he list (i think chris simply hit reply...) : )
Am 11.09.20, 09:27 schrieb "Christofer Dutz" <christofer.d...@c-ware.de>:
And my only concern about native-drivers is that I want to prevent us
from becoming lazy.
I know we had the EIP and Modbus drivers by using external libs and
that wasn't very pleasant (At least not for me)
We were relying on libs we had no control over. It got us to the point
where we could support these protocols,
But looking back it cost us (mainly me) way more time in supporting
them than it would have cost me if we had implemented the parts we needed.
So I would generally say:
- If it’s a technical problem preventing us from implementing it fully
in plc4x (CAN, Profibus, ...) then this is the way to go ...
- If it's a protocol problem (want to avoid implementing the protocol
in order to save time) ... then we should put it in the sandbox
Chris
Am 11.09.20, 09:01 schrieb "Julian Feinauer"
<j.feina...@pragmaticminds.de>:
Hi folks,
thanks for all the replies and the controversy in here shows that
ist good to discuss the matter, indeed : )
I like Cesars way of putting it (which is pretty close to mine)
that PLC4X is a unified API.
This is the Killer thing here.
And what we currently do and mostly did was "PLC4X native". Because
we get all these nice benefits of controlling everyhting and doing code for all
languages.
But, we may end up in situations where there i seither no
possiblity to do a native implementation (profinet, profibus, CAN, ...) where
we need some kind of special hardware where I would like to still have it in
the project.
This would mean that there is some special setup instruction how to
setup the "native" part and then there is some glue code (could easily again be
plattform independent) like a PLC4X generic driver (@Christofer Dutz a bit like
what we reasoned about with PLCnext) which "binds" them together.
As we are really small on man-power and maintainers I think it is a
good and reasonable way to go with a "integrate whats already there" instead of
a "try to find the single silver bullet and die in beatuy".
So my reasoning at the moment is to place something like this
wrapper as native code in a generic section somewhere in the "PLC4X native"
part, that it can be integrated. But then host install instructions fort he
"agent" or proprietary part somewhere else in an "integration" part (not like
integration into other downstream systems but integration of other
communication layers).
Is this something which sounds acceptable for the community are
there feelings against it?
Julian
Am 11.09.20, 02:20 schrieb "Ben Hutcheson" <ben.hut...@gmail.com>:
Hi,
I agree with Chris, having new drivers in a contrib section
would be a good
idea to make it clear that it hasn't been developed as much as
other
protocols or that there is some constraint excluding it from
the main
driver section. The worst that could happen is that it gets
culled
eventually because it isn't maintained and no one else shows
interest.
What protocol is it?
I'm assuming you've already set your mind on developing it, but
something
to consider. Is anybody else likely to want to use it to
warrant spending
time on it? Is there a spec that is published? Does the
manufacturer change
the protocol often? Can they provide information on the
protocol?
Kind Regards
Ben
On Thu, Sep 10, 2020 at 5:03 PM Łukasz Dywicki
<l...@code-house.org> wrote:
> It is pretty good question to answer. Given that Julien
proposal
> includes native binary I can also add that socketcan stuff I
am working
> on .. is bound only to Linux due to native dependency in
JavaCAN transport.
>
> From my perspective I can tell that it really depends on
budget you
> have. Our CAN journey started from CAN over Ethernet (UDP)
and ended up
> in dark corner which some of you could observe over past
weeks. We had
> to do it, because that was customer requirement (skip vendor
gateway).
> If you don't have such requirement then I would say there is
quite weak
> case to invest in it.
> My point comes from observations. I wrote couple of MSpec
files and it
> was indeed fun. Both profinet and lldp took me a little bit,
but
> structures I got structures and I was able to parse real
traffic. What I
> skipped in my earlier attempts was implementation of driver
api where
> you actually start implementing necessary conversation logic.
Having a
> fresh look from CANopen perspective - it is quite big effort
which
> requires time.
>
> My point outlining above is simple - as long as we have just
one
> dominant language as we have and we fail to attract more
diverse pool of
> people to start writing conversation logic for other
languages does not
> give big benefit. I agree it is important, but it is much
more necessary
> now to support wider pool of end devices. Once we will build
big enough
> pool of people who have commercial interest in moving stuff
between
> operating systems and platforms we will be able to start joint
> investment together. There is no better explanation than
savings on
> hardware when it comes to large scale deployments.
>
> From my point of view - I would welcome your stuff anywhere,
even in
> sandbox. Just remember to unify DLL loading logic. ;-)
>
> Best regards,
> Łukasz
>
> On 10.09.2020 00:32, Cesar Garcia wrote:
> > Hello,
> >
> > I think the concept of the project is clear:
> >
> > "PLC4X is a set of libraries for communicating with
industrial
> programmable
> > logic controllers (PLCs) using a variety of protocols but
with a shared
> > API."
> >
> > If your client allows you to publish the project in PLC4X,
it is a very
> > important opportunity for this project to increase and
share knowledge.
> >
> > As for DCOM, it is a reality that will be with us no less
than 20 years
> in
> > the future due to its installed base [1]. We need to live
with the
> Windows
> > and Linux environment for years to come, and that is a
reality.
> >
> > As for solutions with DCOM we have [2], in my case which
allows using
> > OPC-DA from Java, as in [3].
> >
> > My grain of sand
> >
> > 1.
> >
>
https://opcfoundation.org/wp-content/uploads/2018/02/ARC-Report-OPC-Installed-Base-Insights.pdf
> > 2. http://j-interop.org/
> > 3. https://www.eclipse.org/eclipsescada/
> >
> > El mié., 9 sept. 2020 a las 8:31, Otto Fowler
(<ottobackwa...@gmail.com
> >)
> > escribió:
> >
> >> I think this should be hosted and more importantly
_maintained_ outside
> >> the project. If you want to add reference to it to the
project site or
> >> something, that would be something to talk about.
> >>
> >>
> >> On September 9, 2020 at 08:28:12, Stefano Bossi (
> stefano.bo...@gmail.com)
> >> wrote:
> >>
> >> Hi,
> >>
> >> personally I think this kind of approach will limit the
usability of the
> >> library in a very narrow subset of uses do to the windows
operating
> system
> >> dependency.
> >>
> >> I think you guys put a lot of effort in portability and
small footprint
> of
> >> the library and this is a great think in the industrial
world where
> >> typically there are small PC or embedded one.
> >>
> >> Using the library in a small PC like a Rasperry Pi with a
linux distro
> and
> >> a lot of attention for the security and hardening of the
environment I
> >> think is a pro for any industrial project
> >> (e.g. Selinux, Firewall, minimal service installation,
OSCAP security
> >> profile compliance, etc ).
> >>
> >> Evaluating the effort required in reversing the DCOM
protocol is
> something
> >> to be taken into consideration before integrating a
windows library in
> the
> >> plc4x code.
> >>
> >> Maybe this could be a transient solution or a way to
validate a full
> open
> >> source solution.
> >>
> >> Regards,
> >> Stefano
> >>
> >>
> >>
> >> On 09/09/2020 13:35, Christofer Dutz wrote:
> >>
> >> Hi Julian,
> >>
> >>
> >>
> >> the issue I see here is that it will make the build more
complex (the
> >> part using the wrapper will only be runnable on windows
and not sure
> >> if the license of the wrapped DLLs would allow including
them).
> >>
> >>
> >> It will also eliminate the ability to auto-port the driver
to other
> >> languages.
> >>
> >>
> >> And, beyond that, it would limit these drivers to only
work on a
> >> subset of platforms (Aka ... a Java Driver that only works
on Windows
> >> Systems with installed subsystem for the PLC)
> >>
> >>
> >>
> >> I wouldn't want to make such a solution a first class
citizen (aka
> >> live in plc4j/drivers) ... we could sort of start
providing some sort
> >> of "plc4j/contrib" modules, if we have to go this path.
> >>
> >>
> >>
> >> But personally I would opt for at least having a look at
the path I
> >> described in slack:
> >>
> >>
> >>
> >> - Use the native libs and build an application that does
the basic
> >> interaction with the Windows DLLs
> >>
> >> - Use WireShark to record the communication
> >>
> >> - Have a look if it's not just a very small subset of DCOM
that is used
> >>
> >>
> >>
> >> Perhaps it would sort of be like using some mspec types
with a lot of
> >> const fields to allow communication without any
intermediate DLL ....
> >> this would make it runnable on all target platforms and
auto-portable
> >> to all target languages of PLC4X.
> >>
> >>
> >>
> >>
> >>
> >> Chris
> >>
> >>
> >>
> >> Am 09.09.20, 09:50 schrieb "Julian Feinauer"
> >> <j.feina...@pragmaticminds.de>
<j.feina...@pragmaticminds.de>:
> >>
> >>
> >>
> >> Hi all,
> >>
> >>
> >>
> >> wanted to bring it tot he list as we already had a
discussion in
> >> the slack channel.
> >>
> >> We have a project where we consider integrating
machinery in our
> >> system.
> >>
> >> The machinery offers an SDK for communication which is
windows
> >> only and based on DCOM.
> >>
> >> Thus, the integration would be a wrapper around the
SDK with
> >> „only“ a PLC4X „frontend“.
> >>
> >>
> >>
> >> Personally, I consider this viable as our aim ist o
have one
> >> interface for „everything“.
> >>
> >> Nonetheless, I also agree with everybody saying that
its not as
> >> nice as having the complete stack in our hands.
> >>
> >>
> >>
> >> What do others think, should this be part oft he PLC4X
project or
> >> should we just do it separately.
> >>
> >> Personally idk that much but think it would be nice to
have
> >> maximum support in plc4x, if possible.
> >>
> >>
> >>
> >> Best
> >>
> >> Julian
> >>
> >
> >
>
