NX8 v2 problem...

["Proguard Security" <proguard@xxxxxxxxxxxxxxx>]

At one of my Caddx installations i've got a problem but i do not know the
reason.
Randomly, without any obvious reason, the system cannot arm even if all the
zones are secure and the ready light is on.
When we put the code the system sends us 3 beeps and the system cannot arm.
System: Caddx NX8 v2 european version with 16 zones (zone doubled)
Any idea??

Thanks in advance

Spyros Kintzonides