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No plausibility check in Route Map

Posted: 18 Oct 2020 21:46
by piet66
The Expert UI/Route Map sometimes shows used routes with hops that do not exist or are battery powered. Both are not possible. Obviously there is no plausibility check.

Re: No plausibility check in Route Map

Posted: 21 Oct 2020 04:20
by PoltoS
May be this is a CRC error (mangled packet that by chance passed CRC check)?

Re: No plausibility check in Route Map

Posted: 22 Oct 2020 10:20
by piet66
These are corrupt packets, no doubt. And the display is relatively unimportant.

But it leads me to the question, how does ZWay detect corrupted packets and what does it do with them.
When a hop is wrong, the probability is high, that at least one other part of the packet is also wrong, for example sender or class number or sensor value.

Seems that ZWay doesn't use all possibilities to filter those packet.

Re: No plausibility check in Route Map

Posted: 24 Oct 2020 02:43
by PoltoS
Z-Way does not detect corrupted packets. It checks the consistensy of Serial API communication (Z-Wave chip <-- UART/USB --> RPi/PC). The RF consistency is checked by the RF module, means Z-Wave chip SDK, so if the latter accepts the packet (double corruption that leads to valid CRC), Z-Way can do nothing ;(

Re: No plausibility check in Route Map

Posted: 24 Oct 2020 11:49
by piet66
But the chip can only check the formal consistency.
If it is possible to check logical consistency additionally, why does Z-Way not do that?

Re: No plausibility check in Route Map

Posted: 24 Oct 2020 17:02
by PoltoS
It is quite hard to define. You need some apriori information.

But better to uses 5th gen or 7th gen devices - they use CRC16 instead of CRC8. So this problem is not relevant anymore for new installations