Specifications
Selecting a Phone Line
71
Trunk Cards and Connections
Selecting a Phone Line
This section provides information that relates to the telco side of the paging terminal. It 
contains detailed connection listings for the RJ21 trunk connectors located on the 
backplane of the paging terminal that are used to make the connections to the telephone 
company lines. It also tells how the trunk cards operate and how to configure a trunk card 
for DID, E&M, or E-E operation. Adjustment procedures are given for the trunk cards as 
well as for the optional dial click cards. 
This section should help you and your telephone expert provide an appropriate telephone 
connection. Support Engineers at Zetron are available to help you through the telephone 
service selection process. Different types of telephone lines can be connected to the Model 
2100/2200, requiring specific interface card settings; End-to-End (loop start or ground 
start), selector level, E&M Tie-Trunk, or a local phone. 
Support for T1 Trunks
When the number of telephone lines being brought into a single location grows large 
enough, it becomes very attractive to switch to a more efficient method of supporting the 
call density. The Digital T1 Interface option for the 2000 Series paging terminals provides 
a way to do this. The initial and on-going costs for a T1 trunk are significantly lower than 
those for the equivalent number of conventional lines or trunk lines. The installation of the 
T1 interface is sufficiently different from the typical trunk cards that it is covered in its 
own documentation. For detailed information about installing this option, please see the 
2000 Series T1 Interface Technical Manual, part number 025-9271.










