Specifications

Page 1–8
FOCUS System Manual
1.18 Sub-rate Data (SRD)
Module
Three versions of the SRD Module are currently
available. The SRD-2 Module provides two RS-
232 data circuits per DS0, and the SRD-4 Module
one RS-232 and one RS-485 circuit per DS0. Both
versions support a total of four 0-9600 bps asyn-
chronous data channels over two DS0 channels.
The four circuits operate independently of each
other, simultaneously carrying their data/control
signals over two FOCUS DS0 channels, or time
slots.
The SRD module does not process the data
passing through it. Data and modem control
signals, such as those in Table 22-1, are trans-
ferred transparently across the FOCUS DS0
channels.
The SRD-4N includes circuitry to permit
networking RS-485 LANs between substations.
1.19 FOCUS Communications
Agent (FCA) Module
FOCUS can be connected to an Ethernet LAN via
the FCA module and rear interface using FCS
version 3.6 or higher and either Maintenance
Module Versions 5 (MV5), 4 (MV4) or 3 (MV3),
which connects to the front serial port of the
maint. module).
The optional FCA module enables your FOCUS
equipment to communicate with management
systems using SNMP version 1 communications.
Communications can be within a network loop or
between one network loop and another. SNMP
management application tools are available from
several vendors for administering the configura-
tion of events notification (traps) and recipients of
traps.
1.20 Ethernet Switch (6NE)
Module
The 6NE module allows connection of any IEEE
802.3 10/100 Ethernet compliant device to any
FOCUS chassis extending the Local Area
Network (LAN) via the FOCUS system. A single
6NE module allows the user to route to two inde-
pendent T1/E1 interface links, allowing a true
add/drop using just one 6NE. Ethernet switching
functions ensure that data will be transmitted to
the corresponding remote devices only, reducing
unnecessary traffic through the T1/E1 link.
1.21 RS-422/V.35 (6NR/6NV)
Module
The 6NR/6NV module can be used wherever
synchronous bandwidth greater than a single DS0
is required. This is typically referred to as frac-
tional T1/E1.
1.22 Data Channel Unit (DCU)
Module
The DCU module is a DDS (Digital Data Service)
channel module. It provides the interface between
a DS0 timeslot of a T1 stream and a 4-wire
metallic wire network. For example, you would
use a DCU module between your FOCUS system
and a CSU/DSU controlled circuit, or another
FOCUS chassis with a DCU module connected to
a metallic wire network.