Hi Ben,
while I just updated the Modbus documentation I noticed your recent additions
aren't documented anywhere.
I could probably do it, but I would feel more comfortable if you could do so as
you actually understand the stuff :-)
Would be super awesome, if you could add the description of
Hi Ben ...
I just merged your pull request ... currently doing the full build with all
tests but so-far it's looking good.
Thanks a lot for this.
Chris
Am 17.07.20, 10:34 schrieb "Christofer Dutz" :
Hi Ben,
I just reviewed your changes and I like them a lot ... I did find some
Hi Ben,
I just reviewed your changes and I like them a lot ... I did find some minor
things that might deserve tweaking.
But thanks for that :)
Chris
Am 17.07.20, 05:14 schrieb "Ben Hutcheson" :
Hi,
Sure I'll give it a shot,
I have created a pull request to be able to use the
Hi,
Sure I'll give it a shot,
I have created a pull request to be able to use the (01, 0x1,
11, etc..) address formats as well as to change the minimum address to
1. Corresponding to 01 or the first coil.
Please don't hold back on criticizing it, it is the only way I'll learn.
Aaaahh ... perfect
Thanks Ben and Niclas.
Guess I'll be doing some Modbus coding pretty soon :-)
But if someone wants to try I'd be more than happy :)
Chris
Am 16.07.20, 11:48 schrieb "Ben Hutcheson" :
Hi,
*I think we have 6 separate memory areas. Do you have a mapping, That I
Hi,
*I think we have 6 separate memory areas. Do you have a mapping, That I
could use? I mean which first digit represents which memory area?*
I thought there were only 5 areas?
0x - Coils
1x - Inputs
3x - Input Registers
4x - Holding Registers
6x - Extended Registers
I've seen the IEEE format
For floats, I have only seen IEEE format. But can't rule out other.
On Thu, Jul 16, 2020, 14:57 Christofer Dutz
wrote:
> Guess it should be possible for plc4x to interpret INT as two shorts long
> as four... In that case it could probably also handle half precision floats
> (16 bit), full
Guess it should be possible for plc4x to interpret INT as two shorts long as
four... In that case it could probably also handle half precision floats (16
bit), full floats and double, if the encoding is somewhat standard (which I
assume it's not)
Chris
Von:
To make things worse, there is equipment on the market with both 32-bit
numbers as well IEEE floats.
And many clients are incapable of doing something meaningful with those...
And then there is equipment that uses one register to indicate the
magnitude of one or more other registers, say
Hi Ben and Otto,
First off all, thank you Ben for that very detailed explanation. It does seem
as if we should extend the parser to support the different numeric variants. I
don't see any problems in supporting both the hex-like one as well as the pure
numeric one.
I think we have 6 separate
Don’t forget embedded protocols are possible,
different devices format floats differently
some devices don’t want persistent connections
etc etc
On July 15, 2020 at 20:48:39, Ben Hutcheson (ben.hut...@gmail.com) wrote:
Hi,
Answering some of the questions:-
*I guess what would be interesting,
Hi,
Answering some of the questions:-
*I guess what would be interesting, would be what address is going over the
wire for "30001" for example.*
The address that gets sent over the wire is the address starting from 0 i.e
31 would be address 0. I didn't know that.
*Also as a register is
Let me try again; There is no 3 addresses in the products. It is a
notation written with text, by people. the first written digit convey the
type. That's it.
Long time ago, back when the Modbus came to life it was simply a memory
area that one could read and possibly write. And then
Hi Niclas,
Protocol-wise the numbers could be up to 65535 as they use an unsigned 16 bit
integer as an address.
I guess what would be interesting, would be what address is going over the wire
for "30001" for example.
Also as a register is always a 16 bit value, the increments by two sort of
It is a common format in equipment documentation. I am currently working
with an electric meter. See screenshot from its manual;
https://ipfs.subutai.io/ipfs/QmPsra6ExrkSX9GCYWgHa6CTfJbBnddLVXJ3NmJjmAYrAk
At protocol level, there are no such "high numbers", just that the industry
got used to
Hi Ben,
please excuse this potentially stupid question ... so would you suggest we leave
things the way they are or should we change something?
Right now we're using the modbus address syntax, ignoring any potential mapping
strategy.
I guess we might think about adding different address parser
Hi,
I've new but been listening to this conversation, this issue always pops up
when setting up Modbus communications.
I would vote for the API using the modbus register 41, 01, etc..
The translation between modbus registers and the address in the
PLC/simulator is handled within the
Hmmm ...
Regarding: 10012 being a coil and 4 a register.
Well the coils and registers are completely different things ... They are
accessed via completely different requests.
That might be some sort of convenience convention, but I wouldn't call that a
standard (I've actually never seen
Personall, I prefer that Register Numbers are used in APIs and that the
address is only seen if you analyze the over-the-wire format, but maybe
that is just me. A big reason for this is that any interface presented to
an operator would need to use RegNumbers, as most (possibly all)
documentation
Hmm .. so are we doing it correctly?
I mean Wireshark isn't the ideal reference here as I have several valid packets
in the KNX space, where WireShark just says "corrupt package".
So if you enter an "holding-register:42" address it tries to read the register
number 43 in ModbusPAL.
I guess as
The issue with 1-offset is that the "Register Number" found in
documentation is at an "Address" one position less. So Reg 41 has Address
40. Som libraries expect Register Numbers and some expect Register Address.
And every so often, one mixes that up.
On Wed, Jul 15, 2020 at 2:53 PM Christofer
While looking for more Infos I found out I once wrote a tutorial page for PLC4X
__
https://plc4x.apache.org/users/plc4j/virtual-modbus.html
I so totally hate searching the web and getting my answers answered by myself.
Chris
Am 15.07.20, 08:31 schrieb "Christofer Dutz" :
Hi
Hi Niclas,
when preparing a workshop for the Building IoT we were looking for something
where you could simulate a Modbus Slave.
Most of these were Windows only solutions, so ModbusPAL was one of the very few
solutions that were pure-java.
Don't quite understand what the thing with the offset
What is ModbusPAL?
The 1-offset in Modbus has caused a lot of confusion over the years.
On Tue, Jul 14, 2020 at 11:03 PM Christofer Dutz
wrote:
> Sorry for the noise ...
>
> this was a false positive ... the driver was doing things correctly.
> It seems the ModbusPAL was just off by one ;-)
>
Sorry for the noise ...
this was a false positive ... the driver was doing things correctly.
It seems the ModbusPAL was just off by one ;-)
Chris
Am 14.07.20, 15:51 schrieb "Christofer Dutz (Jira)" :
Christofer Dutz created PLC4X-214:
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