I’m using an iPad with the perspective app to run a machine that from time to time will be unplugged and moved to a different place. The gateway PC and PLC will therefore be powered down, but the iPad remains powered on - as soon as it loses the gateway connection it indicates as such, but takes no other action.
What I’d ideally like is for the session to navigate back to my “startup” page as soon as it loses connection*, which is just a branding ‘splash screen’ of sorts which gives some basic information about the startup procedure that is run through when the machine is powered back up. Then when the connection is restored, you immediately see the progress of the startup.
I don’t imagine that this is possible, as with no gateway to serve up the page, it’s not likely to be able to load it. Unless there’s some way of caching that page? And then, of course, is there a way to detect the gateway disconnection from the perspective session and take some sort of action?
Assuming the above is not possible, can I at least detect the gateway reconnection, and take some action on that event?
At the very least, I can detect the “startup procedure active” tag becoming true, and configure an action - but I’m not sure how to get the session ID when the event trigger would be at the gateway level. In my application, I only have a single perspective session license, so there’ll only ever be one - but even if that changed and there were multiple, I’d like to force all active sessions back to the loading screen.
*I know that in most applications this would be undesirable. Our machine is very small, will be used in small rooms, and the WAP that the iPad connects to is built in to the machine. It has a range of about 50m, and the operator will be within 5m of it 100% of the time. So unless someone takes the iPad to the bathroom down the hall and is still trying to run the machine, there should be no networking issues. Initial tests have shown it to be extremely reliable, so we’re confident that this approach won’t give much, if any, grief.