Electra Elite IPK II Document Revision 1General Description Manual - iii______________________________________________________________________________________________________________________________________________________________________General Description Manual iii___________________________________________________________________________________9.1 Dial Pulse Address Signaling ..................................................... 5-169.2 Dual-Tone Multifrequency (DTMF) Address Signaling ............... 5-17Section 10 External Equipment Connection .............................................. 5-1810.1 Music Source for Music on Hold via KSU ................................... 5-1810.2 Music Source for Station Background Music via COI ETU ........ 5-1810.3 External Paging (Audio) ............................................................. 5-1810.4 External Tone Ringer/Night Chime Output ................................. 5-1810.5 SMDR Output ............................................................................. 5-1810.6 PC Connection ........................................................................... 5-1810.7 Relay Contact ............................................................................. 5-18Section 11 Battery Backup .......................................................................... 5-1911.1 System Backup .......................................................................... 5-1911.2 Memory Backup ......................................................................... 5-19