OK, I'll try try it with my own UUID rather. I don't need my task to run at exactly 5 second intervals, it's a simple task which updates only a few parameters but it needs to happen quite regularly. I think the scheduler works well enough for my purposes here, I don't expect it to be precise.
I realise that check will occur with every request, it's not ideal but it's simple and it works and I don't expect my server to be *that* busy that it can't handle it. All the same I might actually change it to use cron @reboot instead, i just want to keep things as simple and as automated as possible. Thanks again for all your comments, you've been extremely helpful. --

