The DS 2040EP makes an additional 20 channels available to the DS 1640 to provide a total of 36 channels. Only one Expansion Panel can be utilized with each DS 1640 in the system. The new ASL Digital Intercom system marks a breakthrough in providing efficient, reliable communications for demanding live production and event management applications. Thanks to innovative use of the newest networking technologies, the ASL Digital Intercom system looks elegantly simple at first glance. But don’t be misled by the remarkable ease of use. ASL Digital Intercom also offers exceptional performance, enhanced flexibility, and user features never before seen in any intercom – analog or digital.