The ATLAS 550 Octal E&M module provides eight ports for 2-wire and 4-wire E&M applications for PBXs, key systems, and leased line analog modems. E&M signaling types I, II, III, IV, and V are supported, as well as a Transmission Only (TO) mode. Type V signaling can be utilized for press-to-talk applications. The module is intended for on-premise applications and therefore makes no provision for sealing current. Signaling originates on the E-lead. The Octal E&M module can be used in ATLAS 550 applications utilizing dedicated, ISDN, T1, and Frame Relay circuits. Each port provides an RJ-45 interface and can be independently configured. The module installs in any of the four user interface module slots in the ATLAS 550 and is flash upgradeable.