there is many ways how to access the Simens but I'd like to know what is the best way in your opinion and also not all methods were explored by myself...
- CoDeSys does not support OPC client (need it!) so it needs OPC as mediator. Not so comfortable and useful for a lot of applications.
- yep you can access DBs in S7 by ISO over ethernet (S7 comm), but there is no whitepaper for it and also in basic CoDeSys can't use C code to implement it.
- is there any solution for S7 comm?
- profinet can be used in CoDeSys but how can it be configured for data exchange?
- Also there is nothong about licensing - Profinet is free to use in CoDeSys?
Also we have modbus TCP, you can setup your own TCP data exchange etc. But in basics we are looking for a lotion without accessing the S7.
you can using kepware or opc matrikon to serve as middle man to exchange data between Siemesn and codesys via OPC UA.
in fact if you study the protocol of S7 ISO you can build your own drive. In fact codesys can work together with C code(if you using control win).
The most simple way, you can configure the codesys as server or so call slave, then configure the data size that need to exchange. in codesys you can export the gsdxml file and import into siemens.
Or you can using a PN/PN couple configure both as master.
If using control win the profinet is free and come with it.