The extension module AMC2 4W-EXT is equipped with four Wiegand type reader-interfaces plus eight inputs and eight outputs. Hence with the AMC2 4W-EXT it is possible to double the number of readers on an AMC2 4W from 4 to 8.

The AMC2 4W-EXT can not be deployed as an independent controller but only as an extension module for the AMC2 4W. Control and access decisions and bookings are carried out by the AMC2 4W alone.

The AMC2 4W can be extended by a maximum of one AMC2 4W-EXT plus a maximum of three I/O extension modules. The I/O extension modules AMC2 8I-8O-EXT, AMC2 16I-16O-EXT, or AMC2 16I-EXT (in any combination) are, like the AMC2 4W-EXT, connected via the AMC2 4W's extension interface (RS485). As the extension modules contain neither memory nor display they are controlled and monitored entirely by the AMC2 4W.