INSTALLATION-CONFIGURATION SECTION 100-816-203 MARCH 1993 DK16 WORKSHEET 3, PERIPHERALS AND UPGRADES (continued)
HHEU: Total
One HHEU must be installed in each digital and electronic telephone that supports a headset or connects to
an HESB for the Loud Ringing Bell feature. See HESC-65A.
HVSU2 or Combined HVSWHVSI: Total
Electronic telephones must be equipped with either the HVSU2 assembly or the combined HVSU and HVSls
assemblies to receive Off-hook Call Announce. See EOCU under Miscellaneous Peripherals.
PDIU-D12: Total for 2000-series Digital Telephones;
PDIU-Dl : Total for 1 OOO-series Digital Telephones
Digital telephones must be equipped with a PDIU-D12 or a PDIU-DI to transmit and receive voice and data
calls. (If Add-on module is installed, then PDIU-D12 cannot be installed.)
Miscellaneous Peripherals
DPFT: Yes or No
The DPFT provides a means to connect eight selected CO lines to standard telephones if there is a power
failure. (PSTU must be installed in Expansion Unit)
EOCU: Yes or No
An EOCU must be installed on a PEKU or PESU that is connected to electronic telephones which are equipped
to receive Off-hook Call Announce. See HVSU2 and HVSWHVSI in Telephone Upgrades.
HESB (Amplifier/Speaker): Total
1. One HESB and HHEU is required for each digital and electronic telephone with the Loud Ringing Bell feature.
2. One HESB is optional to provide single-zone external page connected to the Base Units 600 ohm external
page output. (Customer-supplied amplifiers/speakers may be used in place of the HESB.)
3. One HESB is optional to provide a talkback amplifier/page speaker connected to the Base Units 600 ohm
external page output. (Customer-supplied amplifiers/speakers may be used in place of the HESB.) Talkback for
HESB requires an MDFB.
MDFB (Door Phone): Total
The MDFB plugs into the DDCB to provide a door phone. Each DDCB can support up to three MDFBs; a
maximum of two DDCBs can be connected to the system. Each DDCB requires a Digital Telephone circuit. The
MDFB may also be connected to the HESB amplifier/speaker to provide page talkback.
3-18