I am looking for information regarding the input lag for switches or buttons connected to Wiren Board 6, i.e. the amount of time between pressing the button and the respective action such as turning on the light, in order to decide whether to opt for simple direct dry contact switches/buttons or use switches/buttons connected to a bus. Reducing this lag as much as possible is of utmost importance to me, since it has a major effect on the overall user experience.
Research so far
I’ve done extensive searching with the help of an online translator and found this thread and the article linked within:
If my understanding is correct, Mr Dubrovin (the author of the article) used the same kind of Modbus RTU switches that I would be interested in, however the input lag was as long as 3–4 seconds, which is far too long for my preference.
In the thread above, Mr @poglazov made a rough estimation of how long a single polling cycle would take given 100 buttons at 115,200 bps, which resulted in a very acceptable 56 ms, however it is also my understanding that further significant lag (tens of milliseconds) is introduced by each device (wall panel with buttons), so the overall input lag may increase considerably with just a few devices on the bus.
Mr @Vyac then added further considerations regarding the maximum baud rate of those specific devices at only 19,200 bps and an additional 5–8 ms lag from switching between panels, however he also noted that it should be possible to transfer the state of all buttons per panel at once, estimating the overall polling cycle length at 170 ms.
Since the above information is about three years old, does anyone please have some new experience with these touch switches from Alibaba or any wall-mounted switches/buttons via Modbus RTU connected to Wiren Board?
I prefer using bus topology mainly to reduce the cable length and because the backlit touch buttons are very aesthetically pleasing and convenient. Ideally, I would prefer an event-based protocol, i.e. without master-slave polling, but I’m not sure what works well in practice, so if you have any alternative protocol recommendations, I would appreciate them (preferably using RS-485 as the physical layer due to its robustness).
Finally, in case of using dry contact switches connected to inputs of let’s say WB-MR6C v.2, could you please tell me the input lag? I’ve done extensive searching on YouTube and it looks like about half a second, but perhaps you have exact numbers.