From what I Read, you are supposed to Start CPR , make a call,
read the screen , and use the defib almost simultaneously
The defibrillators in town centre can be unlocked by anyone in an emergency by calling 999, where the oeprator will tell them a code to retrieve it.
Martin said: "To save a life, call 999 first. You will be told to start chest compressions immediately. These are important as they keep the blood flowing around the body, and keeps the heart alive.
"Once a defibrillator arrives, switch it on and follow the instructions. Modern defibrillators like those being used in the Northampton project not only talk to you but also show you what to do on a small TV screen, so can be used by everyone, whether or not they have had any training, and whether they speak English, or have any hearing loss.
"You cannot do anything wrong. The defibrillator will not work unless it needs to."
this one was in Northampton England .