Hi Mick. We have a Pegasus 524 and it comes with alarm with PIR and tilt and Tracker. The alarm is set by pushing a key fob which causes 2 beeps, first I think is alarm setting and second is tracker. If you set off alarm in error it does not set off tracker as van needs to be moved for about 5 minutes before tracker will report a problem. Make sure that your tracker is registered properly. My dealer faxed my registration form to tracker in front of me when I picked up van. Despite this I had not heard from tracker 6 weeks later and it was only by raising question on forum that I realised that I should have received a letter and membership number from them. I phoned tracker they could not find my details and I had to email a copy. Letter turned up a few days later but presumably my tracker was not working for first 6 weeks.
On thing to note, you can't turn off the PIR so there is now way of leaving tilt alarm and Tracker set without PIR on in caravan. This means that I cannot set tilt alarm and Tracker if I leave our dogs in the van at any time. I have opted not to take the alarm/tracker discount as the insurance insists that alarm and tracker are set every time van is left unoccupied and mine would therefore be uninsured if I left dogs in van for any period.