Ring Communications DXB901 - Manual (Page 5)

JUNE 2001 DIGITAL EXCHANGE BRIDGE DXB901
E5 RING COMMUNICATIONS INC.
DXB901 DIGITAL EXCHANGE BRIDGE
INTRODUCTION
The Digital Exchange Bridge (DXB901) interfaces the Ring-Master CB901 Central Exchanges in
a Double-Stage CB901-2 or a Multi-Stage CB901-M system using Fiber Optic links. By utilizing
spare time slots in the Space Time Switch (STS) each DXB901 will transmit data to each other in
a CB901-2 or to the Bridge Master at the Digital Network Controller (DNC) in a CB901-M to be
routed to the other networks.
OPERATIONAL DESCRIPTION
The DXB901 is installed in the CB901 Central exchange in slot 12. The DXB901 program is not
location dependent and does not require additional programming.
The address of the DXB901 is set on DIP Switch SW2. The bridge does not use the node number.
The network number must match the other nodes it is connected to. The Time Slot is assigned by
DIP Switch SW3 and should be set to 2 using inverted binary code.
The DXB901 can be reset and initialized by pressing SW1. This reset will only affect bridged data
and not the network on the central.
The DXB901 also has 8 LED's for indication of operation and trouble shooting. See Figure E2.
When data on this network contains a destination address not on this network the DXB901 takes
the data packet and when the correct time slot is activated sends the packet out through the Digital
Network Interface (DNI , NFE1692) and out on the fiber to the Space Time Switch (STS) where the
packet is routed by the Digital Exchange Master (DXM901).
A spare Pulse Code Modulation (PCM) highway is used to connect the Bridge Master to the STS
and must be programmed on site to make permanent connections in memory to all DXB901's in
the system. This reduces the total number of stages available in the DNC by one. See chapter on
the Bridge Master for additional information.
INSTALLATION
The DXB901 MUST be installed in slot 12 of the CB901. The DNI (NFE1692) will be installed in slot
13 and the DXC901 MUST be installed in slot 11. If DP977 Program Distribution is used, it must be
installed in slot 10, and the NMF6012 four position jumper ribbon M UST NOT be used. This
configuration reduces the total number of subscribers by 16.