I'd be more than willing to setup some equipment for a lab to test with. Readily available to me are a couple of Omron CP1-H CPU's and a Red Lion G3800C (which is outdated, but communicates with everything ootb), plus I can easily get some Modicon stuff as well. The Omrons are fitted with serial ports capable of communicating RS-485 in modbus RTU, and the RLC HMI can talk Modbus TCP as well, so that is without laying my hands on some Modicon equipment.
Let me know, and I can start pretty much as soon as I clear space on my lab bench for the setup. Stephen On Mon, 2021-08-16 at 11:44 +0000, Christofer Dutz wrote: > Hi Stephen, > > it's not that we're dropping anything ... it's just that we haven't > put any work into creating such a driver. Some day, if someone > stumbles over PLC4X with the need to use ASCII, we might implement it > for them (Mabe as a paid-gig or not). > > In the inital days of PLC4X I invested a huge amount of time into > thinking what the industry could need ... I switched to the way more > healthy mode of implementing was is actually needed and when it's > needed. > > But I agree ... Modbus TCP, Modbus RTU (over RS or TCP) are > definitely flavors we should be supporting. > > Chris > > > -----Ursprüngliche Nachricht----- > Von: Stephen Snow <s40...@gmail.com> > Gesendet: Montag, 16. August 2021 13:39 > An: dev@plc4x.apache.org > Betreff: Re: Modbus RTU > > So I use modbus in all it's flavours, including modbusRTU and Modbus > TCP. And the newer flavours Modicon is using now. Modbus RTU is > definitely in heavy use on industrial equipment I encounter. It is > commonly a drive networking choice, and a HMI networking choice. So, > depending on what is using it ASCII is likely needed too. The one > thing you don't want to do is drop ASCII. > > Regards, > Stephen > > > On Sun, 2021-08-15 at 23:48 +0200, Niclas Hedhman wrote: > > On 2021-08-15 22:40, Łukasz Dywicki wrote: > > > Then each driver flavor of modbus (rtu, ascii, tcp) would simply > > > need to wrap and unwrap structures coming from an transport. > > > > seeing the ascii variant since the 1980s or early 1990s. IIUIC, it > > was > > mostly used for hand terminals, and not to connect to computers. > > So I wouldn't spend time on that, unless nothing else is around. > > > > I haven't checked the mspec in details, but I suspect it is close > > to > > fair amount of equipment has extensions that are not in the > > specification (well, at least last time I read it about 20 years > > ago), > > namely floating point numbers and 32/64-bit integers. It would be > > neat > > to support that... > > > > Unfortunately, I don't have cycles to help out with it. > > > > Cheers > > Niclas > >
