Abstract: An application module interface is disclosed that allows one or more modules to access voice or data channels in a private branch exchange environment that contains one or mole B channels (bearer channels) for transmitting voice or data signals, and one or more D channels (signaling channel) for transmitting data. The application module interface provides a control channel that allows a module to obtain and vary the status and configuration of a telephone terminal. The application module interface provides access to both directions of two B channels (B1 and B2) and one D channel. The application module interface is the only interface required to connect the two B channels (B1 and B2) and one D channel to or from the telephone terminal and the add-on module. A frame format includes a start bit (logic “1”), a number of data bits allocated to the D channels (D, D?) and B channels (B1, B1?, B2, B2?), and eight stop bits (logic “0”).

Abstract: An application module interface (AMI) allows one or more modules to access voice or data channels in a private branch exchange (PBX) environment. The AMI provides a control channel that allows a module to obtain and vary the status and configuration of a telephone terminal and permits communications with the application module(s) connected to a telephone terminal. A frame format includes, for example, a start bit (logic “1”), three control channel bits, C, and eight stop bits (logic “0”). The control channel field, C, bits include one flag bit and two data bits. A complete control channel data word is split, for example, over five consecutive AMI frames and contains, for example, a total of nine data bits and a parity bit, transmitted least significant data bit first. The parity bit creates “even parity” for the ten total bits. The flag bit is set to one to indicate the start of a new control channel word, or zero otherwise.

Abstract: An application module interface (AMI) is disclosed that allows one or more modules to access voice or data channels in a private branch exchange environment. The AMI provides a number of hardware signals to the telephone terminal and/or modules. The hardware control signals include module present, phone receiving OK and module receiving OK. The module present (MP) signal indicates that a module is plugged into the AMI electrical interface. The module receiving OK (MOD-OK) and phone receiving OK (PHONE-OK) signals indicates that the module and phone, respectively, is receiving valid AMI control channel messages. The hardware control signals permit the presence of a telephone terminal and/or a module to be detected, as well as to detect the disruption of an AMI connection. The hardware control signals are used to implement a start-up, recovery and tear-down mechanism.

Abstract: An application module interface (AMI) allows one or more modules to access voice or data channels in a private branch exchange (PBX) environment. The AMI provides a control channel that allows a module to obtain and vary the status and configuration of a telephone terminal and permits communications with the application module(s) connected to a telephone terminal. A frame format includes, for example, a start bit (logic “1”), three control channel bits, C, and eight stop bits (logic “0”). The control channel field, C, bits include one flag bit and two data bits. A complete control channel data word is split, for example, over five consecutive AMI frames and contains, for example, a total of nine data bits and a parity bit, transmitted least significant data bit first. The parity bit creates “even parity” for the ten total bits. The flag bit is set to one to indicate the start of a new control channel word, or zero otherwise.