2-20 Chapter 2Hardware DescriptionsiDCS SERIES KEYSET DAUGHTERBOARDS[28D and 18D Keysets Only]iDCS 28D and18D keysets support one of three different types of daughterboards installedon them to enhance operation or to provide an additional local port depending on the type ofdaughterboard.iDCS KDB-Digital Line Interface (FKDBD)If your keyset is connected to a Digital Line Interface (DLI) port that supports2B+D operation, you may install a daughterboard that provides a Digital LineInterface (DLI) port for connection of a digital station device such as a keyset or64 button add-on module.iDCS KDB-Single Line Interface (FKDBS)If your keyset is connected to a Digital Line Interface (DLI) port that supports2B+D operation, you may install a daughterboard that provides a Single LineInterface (SLI) port for connection of a standard telephone device such as acordless phone.iDCS KDB-Full Duplex (FKDBF)The standard speakerphone mode of operation for an iDCS keyset is “halfduplex”. This means that you cannot transmit and receive speech at the sametime. Adding an FKDBF to your keyset will convert the speakerphone into fullduplex mode, enhancing its operation. In addition, the FKDBF may have up tothree external microphones attached to it for conference room type applications.These microphones require an “EXTMIC” key programmed on the keyset toactivate or deactivate them.DOOR PHONE INTERFACE MODULE (DPIM) & DOOR PHONE (Figure 2-22)y The DPIM adapts any DLI circuit for use with the door phone unity Commonly used to request entry through locked doors (interior or exterior) or as a roommonitoring box (a weatherproof door phone is available for external use)y Provides contact control to be used with a customer-provided electric door locky Door phone is wall-mountedDPIMDoor PhoneFigure 2–22 Door Phone Interface Module & Door Phone