Items read at startup

[tfinell]

Hello,

When Smarthome launches, it does not read all the values of the items. I have tried to use knx_init and knx_cache separetly and at he same time, but it does not help. I am using knxd v. 1.4 and Smarthomeng v. 1.4.2.

Could you help how get all values of the items at startup?

BR, Tomas

[Msinn]

Usually I configure knx_cache in the items to do exact that.

knx_cache reads the values form the cache of knxd.

knx_init reads the values from the knx components and should not be used for a large number of items because it floods the knx bus and probably a couple of telegrams get lost.

If knx_cache doesnot deliver all the values you expect, maybe the configuration of knxd is not right. I can't help you with that, since I am no knxd expert.

[mumpf]

Hi,

I would like to point at this Situation:

knx_init reads the values from the knx components and should not be used for a large number of items because it floods the knx bus and probably a couple of telegrams get lost.

Usually all knx_cache Items are filled from knxd cache. If the value is not available in knxd cache, knxd issues a read request on the bus. As soon as the according reply is issued, the Item is updated. But this happens slightly later compared to the cache initialization. The Question here is, if shNG reacts during initialization correctly on replies on the bus?

If we look now on the startup case of the complete system (reboot): Nothing is in knxd cache and shNG is initializing -> the knx_cache behaviour can be compared to knx_init behviour. This ist the case where I observed also some missing initializations in the past (currently I am not using shNG).

My solution to this was to set for each relevant Item cache = true. This does not really help for long offline periods, but for a reboot it helped a lot minimizing wrong values after initialization.

But it would be great, if this problem could be solved for shNG - this behaviour was one of the causes why I switched to callidomus, which does read-requests on each restart of callidomus (there is nothing comparable to knx_cache, just the knx_listen behaviour) and nevertheless there are no wrong values after startup.
But callidomus has a native implemented knx-stack (not using eibd or knxd).

Regards,
Waldemar

[Msinn]

I know from the knxd forum, that people had the problem with lost knx requests/answers (not only from shNG) and for them it was fixed by changing the options of knxd.
If I remember it correctly, most problems were from people using a Weinzierl Gateway or Router.

So, I am not sure, it is fixable in shNG when relying on knxd.

[heckmannju]

Hi,

reading the knxd doc
https://github.com/knxd/knxd/blob/ma...oc/inifile.rst
I assume that the pace feature which limits the amount of packets is one possible solution for this issue.

Best Regards,
Jürgen