Section 700 - Operation Chapter 3. System Features576-13-700 DBS 576 (USA), Revised 6/11/98 35Considerations• The DID Trunk card supports 1 to 4-digit dial-pulse (10 pps) or Dual Tone Multifrequency(DTMF) signaling.• DID numbers must be between 0 and 9999.CO Trunk Interface - Ground StartGround start trunks are supported in the System with the VB-44511 Loop Start/Ground Start trunkinterface. Each card supplies 8 circuits that can be individually configured for either loop start orground start operation.Ground start trunks are useful in preventing call collision.Hardware Requirements• When ground start trunks are used, the -48V power supply is required.Related Programming• N/AConsiderations• N/ACO Trunk Interface - ISDN BRIThe System supports ISDN BRI with the VB-44530 ISDN BRI interface unit. The VB-44530 is a T-Point ISDN-BRI that supports 2 B (bearer) channels and 1 D (data) channel (2B + D; 192kbps). Thisunit connects to an ISDN Data Service Unit (DSU). Point-to-point and point-to-multi operations areselectable.The ISDN-BRI supports enblock setting and enblock setting at the sub-address.Hardware Requirements• N/ARelated Programming• N/AConsiderations• A DSU is required (not available from Panasonic).CO Trunk Interface - ISDN-PRIThe System supports ISDN-PRI with the VB-44540 ISDN PRI Interface unit. The VB-44540 is a T/S-Point ISDN-PRI that supports 23 B (bearer) channels and 1 D (data) channel (23B + D; 1544kbps).This unit connects to an ISDN DSU.Up to 3 units may be installed in a cabinet if you use full channel (23B + D or 24 B). A maximum of18 units may be utilized in a fully equipped system. When all 24 channels on a unit are utilized, 3 slotpositions are required.Hardware Requirements• N/A
