The current generation AUTOMATiQ as well as the earlier Automatic(+) systems use two magnet rings to provide the speed signals. Both the rings are required for correct system functionality, without these the system will not be able to shift.
The sprocket magnet ring (part nr. AUT-ISS-OE for both Automatic(+) as AUTOMATiQ) provides the input speed signal and is mounted on the sprocket retaining ring.
The hub magnet ring (part nr. AUT-OSS-OE for Automatic(+) and AUT-OSS2-OE for AUTOMATiQ) provides the output speed signal and is mounted on the hub and secured with a small screw at 1 Nm magnets facing the flange.
Older Harmony system used only one magnet disc (in black or silver), and used the sprocket itself for input speed. If changing from the old Harmony system to the latest, you must remove the old magnet disc before assembly of the new parts.