CTI Products NCB/EM with External PSTN Modem - Manual (Page 9)

CTI Products, Inc. NCB-EM User Guide
1. Introduction 3
1. I
NTRODUCTION
W HAT IS AN NCB/EM U NIT ?
The Network Combiner NCB/EM TM Module is a wide-area router with one or
two external modems used for L ON W ORKS

networks. The NCB/EM unit is
used in pairs to connect L ON W ORKS

networks real-time, spanning distances
from building-wide to worldwide.. The communication channel spanning the
distance between local networks can be any analog or digitized analog channel
that is capable of carrying V.34 standard modem signaling. NCB/EM units are
available with modems for standard dial-up Public Switched Telephone Network (PSTN) circuits, 2-wire or 4-
wire leased lines, microwave channels, PBX circuits, etc. Data transfer between distant networks via an NCB
module pair is "live", delayed only by the transit time through the routers and modem connections.
The NCB module uses router technology so that no custom coding or additional hardware is necessary to
seamlessly connect multiple networks across very large distances. The NCB module is self-contained, easily
configured with standard network management tools, and requires no custom programming or coding changes
in system nodes.
The NCB/EM unit contains a Modem Controller and a Telephone Directory objects
Basic Application
A basic application of the NCB module is where two multi-node LonWorks networks, separated by a distance
beyond the reach of conventional wired media, need to be interconnected, as in Figure 1. This distance could be
across a large building, business campus, city, etc. Using the NCB module, this interconnection is
accomplished using one NCB module local to each network site and a single voice-grade telephone circuit
connecting the two NCB modules. Additional networks can be added to this unified network by simply adding
an NCB module pair per network.
CA-80070-100
LONWORKS
NODE
LONWORKS
NODE
LONWORKS
NODE
LONWORKS
NODE
NCB
LONWORKS
NODE
LONWORKS
NODE
LONWORKS
NODE
LONWORKS
NODE
NCB
STANDARD
VOICE GRADE
CIRCUIT
BUILDING 1 BUILDING 2
Figure 1 Networks in two buildings connected with NCB modules
LonWorks Network Transceivers
The local LonWorks networks at different sites do not need to use the same network transceiver type. For
example, an FTT-10A network, a TPT/XF-78 network, and a PLT-22 network can all be interconnected by
using pairs of NCB modules with network transceivers matching the local network at each site.
Read this
section to learn
the general
function and
capabilities of an
NCB Router