Hi Luca, I believe the description is reversed regarding which driver is the newer one.
`mesa_modbus` is the **old driver**, while `hm2_modbus` is its **newer replacement**. This was also confirmed in the discussion of PR #3819: * BsAtHome explicitly says that `mesa_modbus` should no longer be used and that users should move to `hm2_modbus`: [GitHub comment by BsAtHome] (https://github.com/LinuxCNC/linuxcnc/pull/3819?utm_source=chatgpt.com# issuecomment-3939278576) * In a follow-up, BsAtHome states that the old driver “has been superseded” and describes `hm2_modbus` as the new driver with better data mapping, data types, translations, device initialization and timing control. * andypugh then confirms: “Yes, mesa_modbus has been superseded, but it still works.” [GitHub PR #3819](https://github.com/LinuxCNC/linuxcnc/pull/ 3819?utm_source=chatgpt.com) So the order is: **`mesa_modbus` → old / superseded** **`hm2_modbus` → newer replacement** Therefore, I think the proposal should be about deprecating/removing **`mesa _modbus`**, not `hm2_modbus`. I was also using `mesa_modbus` while working on my configuration, which is why I initially did not realize that it had already been superseded. -- S pozdravem Zdeněk Zdražil ---------- Původní e‑mail ---------- Od: Luca Toniolo <[email protected]> Komu: EMC developers <[email protected]>, emc-users@ lists.sourceforge.net Datum: 13. 8. 2026 9:29:05 Předmět: [Emc-users] Deprecating the old mesa_modbus / modcompile driver "The Mesa hostmot2 tree currently carries two Modbus drivers. The older one lives in src/hal/drivers/mesa-hostmot2/modbus. You write a .mod file describing your device, run modcompile on it, and it generates and compiles a bespoke realtime component from mesa_modbus.c.tmpl for that device. Documented in docs/src/drivers/mesa_modbus.adoc and modcompile(1). The newer one is hm2_modbus, written to replace it. It is a single loadable driver configured with binary MBCCB files built by mesambccc(1), so there is no per-device compile step. Documented in hm2_modbus(9) and mesambccc(1). Keeping both has a concrete cost beyond the duplication. The old driver is the reason hostmot2-serial.h is an exported public header, which constrains work on the hostmot2 headers generally. The only other user is the mesa-pktgyro-test component, which is easy to adjust. So, two questions. To users: is anyone still running a mesa_modbus setup built with modcompile? If so, is there something it does for you that hm2_modbus does not, or is it simply that the configuration has not been migrated? To developers: any objection to deprecating the old driver now, with a note in the docs and a runtime warning, and removing it after a release? If there is a feature gap, I would rather hear it now and see it closed in hm2_modbus than remove something people depend on. -- *Luca Toniolo* _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users " _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
