Why doesn't HS remember the device link state?

[DC]

When HS is stopped and restarted, it remembers the state of all devices except for UPB device links. Can this be fixed?

[JKaplan]

DC -

It seems to me that the links shouldn't have a 'state'. Links are really (group) commands - not devices - and once the comand is issued, the various devices that participate in the link may go into different states on their own. In other words, you could have a link 'on', while all the devices in it are actually 'off'.

In the HS interface, I see that there is a place to display a status for a link, which isn't quite semantically correct. The closest logical thing would be to show the last command issued by that link (i.e. activate, etc.). I suppose it's possible for HS to remember this across a shutdown/startup, but its not surprising that HS wouldn't update this properly after a restart, since there's no device to interrogate for it's current state.

Now that I think about this, the problem exists with one-way X-10 switches as well, since HS can't know what state the switch is in for sure, so it probably just assumes it's in the state of the last X-10 command issued to it. I imagine other people have also noticed how unreliable the 'status' display is. This should be a LOT better with UPB since it's 2-way and can reliable interrogate the devices.

Best thing would be if HS did the equivalent of the "network verify" command in UPStart each time it started up. Might take a while, though.

Jerry

[UPBseer]

The devices need to be polled for their status. Link status is not conclusive. You can activate a Link and turn something on or off, as Jerry pointed out. If the last Link command was known, the Receive Component table for each device would also have referenced to determine device state.

[DC]

I guess this makes sense. I was thinking that if a link is in "activate" state (ie, the last state change was to "activate" it) then when HS comes back up, the link should be "activated". But, I think you are right. If an individual device was changed since the link was activated, it wouldn't make sense to activate the link again. It makes more sense to put each individual device back into the correct state.

But, one disadvantage to this approach is that I have to be careful using link state to trigger events because HS "forgets" the last state it was in.