Virtual relay channel as inversion

For developers
1

As far as I can see, every relay channel can be inversed but the inversion applies only at the hardware output, so no software inversion is possible using the vertual relay (as far as I can see).

User case: I’ve got a heating pump which of course can be used for heating but also has a cooling mode. The pump has an output that indicates the pump is in coolingmode. My need for an inversion is to switch all thermostats (except for ex. bathroom) to cooling mode. When the output of the pump is off, all thermostats needs to be switched back to heating mode (inversion of the input). Input will be one of the channels from a vmb7in. Other options could be using a software solution aka openhab/nodered, but first I like to see if this can be done with the bus components.

2

Can you add an action to this input that puts the thermostats into Cooling mode while the contact is closed?

3

idd I can, but when the contact is open again, the thermostats needs to go back in to heating mode, the inverse function.

4

Yeah, I see your issue.

Would action 0505 help?

https://www.velbus.eu/downloads/velbus/00_general/guide_velbus_actions_descriptions_en.html#act_0505

https://www.velbus.eu/downloads/velbus/00_general/guide_velbus_actions_descriptions_nl.html#act_0505

5

I don’t think it will work. Another solution would be to put the a virtual relay to “ON” and use the action 702: inhibit when cause is closed. The only problem that will rise than is getting the virtual relay on the moment the installation restarts (a kind of always on situation or an action that will be only on the moment the power comes up)

6

I think you might have to use two actions.

OFF when the Initators closes

And a “delay ON” when the Initator opens (with a 0 delay)?

7

Ok,
solution for now is idd to put the relay off when input high (102) and a 406 with time continious. I can 't find direct a delayed ON when cause closed (probably to fast reading).
Only problem remains is that there has to be 1 cycle from the (cooling) contact to to get the virtual relay in the right condition (want to make it idiot proof :wink: )

8

Stop the bus…

Which firmware are you using with this relay?

I had never “seen” the invert state option in a relay until you mentioned it, so I looked today and saw that it cover all 5 relay channel.

image

So I’ve tried inverting the Virtual channel and assigning a Follow Action, which seems to be working.

FYI

The VMB4RYNO relay has Firmware V 1927

9

It’s the same firmware. The NC option was idd one of my first tries

The hardware ouput can idd be inversed, but on the software side, the state remains.

So a NO relay:
software 1 → hardware out 1, follow state = 1
software 0 → hardware 0, follow state = 0
a NC relay:
software 1 → hardware 0, follow state = 1
software 0 → hardware 1, follow state = 0
With follow state I mean the state which is transferred to another relay when using “moment/follow”

Maybe an idea for the developpers to inverse the transferred state of the virtual relay when using NC, that way a simple invertor can be created :slight_smile:

10

Oh I see…

That makes perfect sense now.

Have you put this forward as a feature request?

https://www.velbus.eu/contact/

11

nope, not yet, just checking if I was missing something :slight_smile:

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