[quote=“AlThePal”]Thanks for that information Kevin. Would you say that using the instance ID is more akin to symbolic addressing or logical addressing? Will it have an impact on performance?
The reason I questioned about your planned use of symbolic addressing is because you said the driver would fall back to that for V20 firmware, whereas the current driver would seem to use logical addressing. Why not use the instance ID for V21 and up and logical addressing for V20 and back?[/quote]
I don’t have any performance measurements yet, but using the instance ID is more similar to logical addressing.
I’m not really interested in implementing logical addressing in the fallback case because it’s undocumented and its use is not advised by AB. It’s also much more dangerous, especially when the program is being changed, if you ask me.
My focus for the new driver is correctness/safety first, even if the cost is performance. The old driver has a long history of bugs and other issues, some of it due to being reverse engineered. It will still be available if the performance hit when connected v20 controllers has too great an impact for your project.
The new Logix driver will be a separate module, with slightly different addressing/item paths than the old driver, so switching to it will be a very intentional (and optional, unless you upgrade your firmware to v21) move that you can then measure and make sure it works for your project.