Subscription to ISY Time Out ?

[trevorst]

Is there a time limit on a REST subscription to the ISY.???

 

I have a subscription setup from a Permanent On iPad mounted in the wall, running Demopad.

The feedback from the ISY works fine at first but will stop working after awhile if there is no activity.

I can setup a Demopad to subscribe at set time intervals if I know that the ISY will time out.

[Michel Kohanim]

Hi trevorst,

 

This is how ISY works:

1. You subscribe using REUSE_SOCKET, ISY keeps the socket open

2. ISY sends a heartbeat event every 120 seconds (you should look for these)

3. If the device does not ACK (TCP level) the event, then ISY tries 2 more times

4. If still no response from the device, then ISY assumes the device is gone and expires the subscription

 

I suspect your iPad might be going to sleep and network connectivity is lost. What I suggest is: look for heartbeat signals, if the next heartbeat message is not received within the max-age duration, then assume that ISY is no longer considering you subscribed. In this case, you should subscribe again.

 

All this said, the main question is why the device is not sending an ACK?

 

With kind regards,

Michel

[trevorst]

Thanks Michel....

[barrygordon]

Michel,

 

I seem to be getting a heartbeat message every 25 seconds. You indicated that it is every 120 seconds.  Where can I adjust this value?

[Michel Kohanim]

Hi Barry,

 

120 seconds is the "max age". i.e. if you do not get a heartbeat in 120 seconds, then you can assume the subscription is no longer there.

 

With kind regards,

Michel