LM5 and KNX integration - how should you work with programming

[dreamcatcher]

I am rather new to both LM5 and KNX, but know a bit about automation and programming.

My electrician has set up the KNX for my house while I have installed the LM5 lite myself. The LM5 communicates well with the KNX bus. I have just started to look into ETS5 to understand its basics.

On the LM5 I've already set up modbus integration with my hvac and heating pump. I've also set up reading of API's for my weather station, public weather reports etc.

In ETS5-Group Monitor I can see the group addresses I've created in LM5 in Destination column. So far it looks good and I would expect the groups are available for the programming. However, I don't see the groups available in the ETS5 program list of group addresses. I am a bit reluctant to mess in ETS5 just yet as I want my electrician to complete his side first, so I believe this is just lack of ETS5 knowledge and that I must add them in some way.

Am I on right track here or have I misunderstood some basic concepts? Is it so that ETS5 can't utilize the data from LM5 so all programming mixing KNX and LM5 must be done in LM5?

An example of a simple task:
Extra air on hvac is now programmed in ETS5 using a relay output going to the hvac. Now that I have established modbus communication to the hvac using LM5 I should be able in ETS5 to use this group address created by LM5 instead...

Furthermore I've been looking around for learning resources to better understand both ETS5 and LM5-KNX integration. I've looked at some isolated ETS5 videos, but not found anything to identify my issue described above.

Please advice me if you know any good starting points for learning all this:-)

[FatMax]

In ETS you create groupadresses that you connect objects from the KNX-equipment in your installation to. You can create group adresses on your LM that no KNX objects "listens to/responds to" and use these for, as per your example, modbus or just GA's you can adds scripts to. These objects to not sync back to ETS, so you need to keep track of both projects so you don't use the same address for different purposes.

[dreamcatcher]

In ETS you create groupadresses that you connect objects from the KNX-equipment in your installation to. You can create group adresses on your LM that no KNX objects "listens to/responds to" and use these for, as per your example, modbus or just GA's you can adds scripts to. These objects to not sync back to ETS, so you need to keep track of both projects so you don't use the same address for different purposes.

Thanks for reply. What I want is to be able to connect the group address defined in LM to a certain trigger in ETS5 (or group of so). Is this not possible?

E.g.
Defined in LM5 is 30/1/1: Hvac max air (modbus)
In ETS5 I already have several triggers which sets a dry contact relay to the hvac. Now I want to just start using the LM5 30/1/1 group address instead of the relay using the same triggers.

[Daniel]

If you already have group in ETS which you want to control from elsewhere then you directly select this group. In example for modbus and a KNX switch. In ETS you have a switch with address 1/1/1 and you have modbus device which you want to control this object (I assume the data conversion is correct) then in modbus mapper you just select group 1./1/1 for the register you want to control it from. If the modbus data needs a conversion of some sort, let say you have byte object and you want to write it to bit, then you need a script to convert it. In such case modbus value would be written to another group address ( I would recommend to use virtual group to not collide with ETS) and then you need a script to convert the values and write to KNX object. As you are a beginner I would recommend you to use Scenes tab and in there you can make basic conversion. This way you don't have to use the script.

[dreamcatcher]

Hmm. It appears that I might have mistaken the basic concepts although I still don't have it confirmed.

I thought I could use the LM5 as a modbus gateway for KNX such that I could access the group addresses set up for modbus on LM5 inside ETS5. Is this not possible?

Furthermore, in ETS5 the electrician has programmed e.g. this Hvac max air setting with one group address connected to the various triggers (KNX buttons and sensors). In LM5 I can see this group address ofcourse, but not the specific buttons etc. related to the KNX hardware. My idea was that I should be able to just use the LM5 modbus created group address in ETS5 instead of the current group address...

If this is not possible I will have to control the modbus group address inside LM5 which is not exactly what I wanted to do...

[Daniel]

LM is a gateway between KNX and Modbus and many more protocols. You always have to collect a data and write it to object.

[admin]

By default LM is a transparent bridge between KNX/TP and any other protocols. Any group message from KNX/TP will appear in LM and vice versa. For modbus control just make sure that your KNX button and LM Modbus mapping have the same group address. It will work automatically.

[dreamcatcher]

By default LM is a transparent bridge between KNX/TP and any other protocols. Any group message from KNX/TP will appear in LM and vice versa. For modbus control just make sure that your KNX button and LM Modbus mapping have the same group address. It will work automatically.

Thanks. I think this confirms that I am missing something in ETS5 and I should be able to achieve what I am thinking about. So I need to figure out how to access the group addresses made in LM5 in ETS5...

[Tokatubs]

Do you have access to ETS5?
If so you just create them manually and link the connections that you want.
GA made in LM needs to be made in ETS5.They will be read on the bus, but needs to be added manually in ets.

[dreamcatcher]

Do you have access to ETS5?
If so you just create them manually and link the connections that you want.
GA made in LM needs to be made in ETS5.They will be read on the bus, but needs to be added manually in ets.

Perfect! Thank you! I will check this out further in the ETS5 (I have access, but since electrician is not 100% finnished I am a bit reluctant to make changes right now - at least until I feel more confident). Still a lot to learn there. Do you have any recommendations on online resources for learning ETS5?

[Tokatubs]

https://wbt5.knx.org/

Check out the knx e Campus. Good place to start.

[dreamcatcher]

I've played a bit more with Modbus, LM5 and ETS5 now.

I have a question about segregation between virtual group addresses and normal. As I don't know what parameters can be useful in the ETS5, I've put all my new group addresses created in LM5 into the 31 address range. Can this cause a problem with the bus load or other unwanted effects? I've seen other places in the forum that some recommend to make virtual addresses. I see that point if you are sure you don't need it in the ETS5, but as long as you are not certain and you want to keep it tidy - then I prefer to put everything in the e.g. 31/*/* address range.

For now I have about 170 new group addresses defined in LM5 on the 31/*/* range. Some are for testing and will be deleted.

This is (for now) what I have created group adresses for:
- Nibe heat pump (modbus)
- Flexit UNI4 (modbus)
- Davis weatherstation (open API)
- Yr.no (open API)
- Some internal LM5 data

[admin]

Virtual objects are outside KNX range so they cannot be used in ETS. In most cases you can disable "write to bus" option for normal objects and use grp.update instead of grp.write in scripts. This won't send values to KNX/TP bus and will reduce bus load.

[dreamcatcher]

Virtual objects are outside KNX range so they cannot be used in ETS. In most cases you can disable "write to bus" option for normal objects and use grp.update instead of grp.write in scripts. This won't send values to KNX/TP bus and will reduce bus load.

Thanks for info. Is it possible to tell when you should start practicising segregation of objects from the KNX/TP bus? I.e. how big a project can be before any practical implications. And what will be the first symptoms of a problem?

[admin]

If the line is overloaded then some telegrams can be lost. You can check the line load statistics in System Config > Network > KNX statistics. To make things easier just use virtual objects for data that is not needed on the TP bus.