New Hot-Swap Supporting 4-Port E&M VoIP Module for AP1800 VoIP Gateway

Various E&M VoIP gateway series of AddPac is approved for its high performance and reliability in world-wide markets. AddPac provides highly advanced VoIP services in order to meet demanding and evolving business requirements of customers. Especially AddPac E&M VoIP Gateway has been developed through more than 15 years of experiences and accumulated know-how from existing enterprises and communication markets. AddPac E&M VoIP Gateway provides concurrent dual VoIP signaling stack such as H323, SIP and QoS for high quality of communication service. New AP-N1-E&M4 4-Port E&M VoIP Module is designed for Hot-Swap supporting next generation VoIP gateway like as AP1800, etc.

First, E&M Type I

Type I is the most common standard type in North America and Japan, etc. An outgoing call to the signaling unit with Battery on the M lead. Incoming calls are signaled by an Earth signal on the E lead.

Second, E&M Type II

The Type II interface requires no common ground; instead, each of the two signals has its own return. For the E signal, the tie line equipment permits current to flow from the PBX; the current returns to the PBX's ground reference. Similarly, the PBX closes a path for current to generate the M signal to the tie line equipment.

Third, E&M Type III

A variation of Type II, Type III use the SG lead to provide common ground. With this configuration, the PBX drops the M signal by grounding it, rather than by opening a current loop.

Fourth, E&M Type V

Type V is a simplified version of Type IV. This is also a symmetric interface using only two wires. Type V requires a common ground between the PBX and the tie line equipment; this is provided via the SG leads.

E&M Type Selection