- Provides interface for (8) digital stations and (2) analog stations- Also provides interface for:- Music-on-Hold or Background Music source- External paging Zone- Equipped with (4) 8-conductor interface jacks.- (2) for (8) digital stations- (1) for (2) analog stations (or Doorboxes)- (1) for Music-on-Hold/Background Music input, and External Paging Zone output, and (2) relay circuit connections.- The above relay circuits are available for:- Door-strike control, when analog ports are used for Doorboxes- Control for Music-on-Hold or Background Music source- Control of External Paging Equipment- Installs only in universal slots 1-3 of Main or Expansion Chassis.- Allows addition of (1) 3-Port CO Trunk Daughter Board (3COIDB) or (1) PRI Daughter Board (1PRDB).- Maximum (3) per Main or Expansion Chassis.- Maximum (9) per system.