Hi Stavros, I think it will be both. You'll need to adjust the mspec https://github.com/apache/plc4x/blob/develop/protocols/modbus/src/main/resources/protocols/modbus/modbus.mspec) however that already contains a serial root node... Perhaps this is already covered. Then we'll need to work on a new driver module.
If you want I could do a one on one zoom session with you. To get you started. Chris Holen Sie sich Outlook für Android<https://aka.ms/AAb9ysg> ________________________________ From: Stavros Nicolakopoulos <rezeb...@gmail.com> Sent: Saturday, April 17, 2021 9:27:27 AM To: dev@plc4x.apache.org <dev@plc4x.apache.org> Subject: Re: AW: Modbus RTU and RTU over TCP You are right about the RTU over TCP -it should be the same as RTU over Serial, just using the TCP transport- but the RTU protocol is slightly different. You don't write the transaction ID, the protocol ID and the data length to the buffer. And then you must compute the CRC (Cyclic Redundancy Check) and add it to the buffer. Does this mean that I have to change the modbus.spec in the protocols module? Or do I have to change the org.apache.plc4x.java.modbus.protocol.ModbusProtocolLogic.java file in the plc4j module (drivers->modbus)? Regards, Stavros On 2021/04/16 11:07:30, Christofer Dutz <christofer.d...@c-ware.de> wrote: > Hi Stavros, > > and welcome to our cool little project list :-) > > As I mentioned on SO I would assume that it should be simple to implement > Modbus RTU as in general it should just be a different encapsulation and the > serial transport, we already have (or in case of RTU over TCP well that > should be the same as RTU over Serial, just using the TCP transport. > > I just checked and all my PLCs except the S7 device support RS458 so I guess > I should be able to experiment with it. > > The only problem is "time" ... > > So, if anyone here in the community or even perhaps you, Stavros, want to get > started on this ... go ahead. > > Chris > > Von: Stavros Nikolakopoulos <snikolakopou...@maseurope.com> > Gesendet: Freitag, 16. April 2021 12:22 > An: dev@plc4x.apache.org > Cc: Stratos Koumantakis <skoumanta...@maseurope.com> > Betreff: Modbus RTU and RTU over TCP > > Hi, > > I'm writing about the following issue, that I posted at Stack Overflow. > > https://stackoverflow.com/questions/66743707/modbus-rtu-over-tcp > > In the Node.js ecosystem I successfully tried the modbus-serial module. > > https://www.npmjs.com/package/modbus-serial > > In the Java one, the only solution I found is the following > > https://github.com/dog-gateway/jamod-rtu-over-tcp > > It would be great if you could implement it in PLC4x. > We love the Scrapper<https://plc4x.apache.org/users/tools/scraper.html> > feature and we would like to use it if the Modbus RTU over TCP was > implemented. > > > -- > Stavros Nicolakopoulos > Senior Software Engineer > [logo7] > Address: 92 Kifissou Ave., Athens GR 10443 > E: i...@maseurope.com<mailto:i...@maseurope.com> │ W: > www.maseurope.com<http://www.maseurope.com/> > T: +30 210 4014000 │ F: +30 210 4001652 > [cid:image002.png@01D732C2.3504F300] > > P Please consider the environment before printing this e-mail > Disclaimer: This e-mail is confidential. If you are not the intended > recipient, you should not copy it, re-transmit it, use it or > disclose its contents, but should return it to the sender immediately and > delete the copy from your system.Mas or any of > its subsidiaries or affiliates are not responsible for, nor endorse, any > opinion, recommendation, conclusion, solicitation, offer > or agreement or any information contained in this communication. MAS or any > of its subsidiaries or affiliates cannot accept > any responsibility for the accuracy or completeness of this message as it has > been transmitted over a public network. > >
