Julian,
actually, the Allan Bradley / Rockwell has a nice feature about "tagging"
variables / memory locations within the PLC itself.
When reading (at least with the library I'm using) I simply say what tag I
want to read (e.g. "speed"), optionally a program name (different tags are
grouped by program, or exist as "controller tag") and all the data type
information associated with it comes back with the value at protocol level.
I haven't dug into Chris' work on PLC4X quite just yet (just too much work)
but I assume it'll work the same as the JavaScript implementation.
I also assume there's a way to list all those "tags", but that's not
implemented quite yet in the library I'm using :-( Luckily I have access to
a WindoSH box with the Rockwell software where (through millions of clicks)
I can actually find the list of tags & such!
Happy to help in any way...
Pier
PS
On Tue, Sep 25, 2018 at 6:30 AM Julian Feinauer <
[email protected]> wrote:
> Hi Pier,
>
> thanks for your kind offer.
> Perhaps you can, yes : )
>
> We had a discussion because the colleagues do not know exactly the program
> on the plc.
> So the question is to what degree we are able to extract sensible values
> from the plc.
>
> I know that for an S7 Controller this is basically impossible as all I can
> request via protocol is an offset and a length from a byte array, so I have
> to know where bits, bytes, ints or doubles are stored to do the right
> "deserialization".
> On the other hand, I learned from the Modbus Protocol that there are
> specific memory areas which are tied to datatypes, so in the case of modus
> it should work to request "unknown" variables and perhaps decipher them by
> comparing their content with whats on the HMI or something.
>
> So my question is how this works for the Allan Bradley / Rockwell
> controller and the Ethernet/IP protocol.
>
> Thank you already!
> Julian
>
> PS.: I will try to find out today what kind of controller this is exactly.
>
> Am 25.09.18, 00:04 schrieb "Pier Fumagalli" <[email protected]>:
>
> I have a couple of Allan Bradley / Rockwell on my desk (Control Logix
> and
> Compact Logix, both series 5xxx) and yes, they're both using
> Ethernet/IP as
> the underlying protocol.
>
> I use https://github.com/cmseaton42/node-ethernet-ip to read from them
> currently...
>
> Anything I can help with? :-)
>
> Pier
>
> On Mon, Sep 24, 2018 at 9:55 PM Julian Feinauer <
> [email protected]> wrote:
>
> > Hey,
> >
> > I talked to a customer today about the integration of a Rockwell
> > Controller.
> > As I remember (and some google confirmed that) is Rockwell closely
> related
> > to Ethernet/IP Protocol.
> > Does anybody have any experience with Rockwell controllers?
> >
> > Julian
> >
>
>
>
