Ping binary sensor group behaviour

Hi I am using a binary sensor group for monitoring a list of servers. All binary sensors are created using platform ping. The group only contains the same type of binary sensors. I am using HA core-2022.3.5.

The group shows all servers as connected and the state of the group is “on”. If I disconnect a server the member of the group shows disconnected, but the state of the group is still “on”.

I use the same system for doors, when all doors are closed the group state is “off” and then turn “on” if one door is opened.
I don’t understand why the binary sensors created with ping behave differently as a group. I would expect if all members of the group are connected the group state would be “off”, if one is disconnected the group state should turn to “on”. Am I misunderstanding group behaviour.

That is the same behavior, both groups are behaving the same. Specifically they are behaving as if the value of all is false.

When all is false (as is the default) the sensor becomes on if any of its included binary sensors are on and is off only if all of them are off. Which is exactly what you are describing in both cases:

  1. one server off and others on = sensor is on
  2. one door on and others are off = sensor is on

This explains how binary sensors calculate their value from their entities when all is true or false.

Thanks for the quick reply. I understand now, finally got my head thinking the right way. I got it working using all: true and triggering based on a change to off/disconnected state.