Help needed - Vista-20P sets to Fault every time I trip door sensor.

[ymg200@xxxxxxxxxx]

Hi all,
I am in the process of installing Vista-20P. I have setup RF Receiver
5881 and registered wireless door sensor to Zone 10.
The problem is that even when the system is disarmed once door sensor
is tripped it starts showing Fault at zone 10. Did I do something
wrong registering the sensor?
Once it faults, it never goes back to Ready state. The only way that I
found out to clear the Fault is to enter/exit the programming mode.
- Why doe it Fault once the sensor is tripped?
- How to clear Faults?

Thank you.