There are four types of Norstar systems as detailed below:
Norstar Compact and Norstar Compact Plus
Norstar Modular and Norstar Modular Plus
Norstar Compact and Compact Plus Control Units
There are two BT Norstar Compact control units which are wall mounted.
The Compact Plus is pictured on the left and is approximately (450mm x 300mm x 150mm).
The original Compact is pictured on the right and is approximately (900mm x 300mm x 100mm).
Norstar Modular and Modular Plus Control Unit
The BT Norstar Modular and Modular Plus control units look the same. The difference is the software.
The Modular Plus software offers a feature to adjust the time for British Summer Time clock change, without the need to enter programming. The Modular software does not support this feature.
To determine which software level your system has, try moving the system clock forward 1 hour.
From a telephone press: Feature **393 (FWD).
The Modular Plus software telephone display will show Forward by 1Hr?
Press the Rls key to exit as we don't want to change the time.
The Modular software telephone display will show Feature: **393 until it times out as the system does not support this feature.