Three operating classes have been standardised, but only classes A and C are really used:
- Class A (All) maximises the life of the object, limiting opportunities to receive messages to two time slots following the sending of a message
- Class B (Beacon) can be used to program additional reception slots so that the Network Server knows when to send messages to the object
- Class C (Continuous) enables the object to receive messages at any time, except when it is sending. This means the battery works hard, and this class is used only for objects with an external power source.