2
Issue 14, April 2003
64200376L1-5A
A compact, NEBS-compliant cabinet suitable for the
customer premises or the central office provides added
safety and reliability. The 2U design uses little rack
space. When wall mounted, the 8.5-inch by 11-inch
chassis occupies a space the size of a piece of notebook
paper. Two Total Access 850 systems can be mounted
side-by-side in either 19-inch or 23-inch relay racks.
Preconfigured packages are available.
Features
The Total Access 850 includes the following features:
• T1/FT1 integrated access
• TDM to ATM migration (RCU)
• Modular network interface (RCU)
• Integrated IP router (RCU)
• V.35 Nx56/64 DTE interface
• DSX-1 card for Dual T1 support (RCU)
• TR-08 signaling support
• Analog FXS and FXO voice expansion (four per card)
• SNMP management (RCU)
• NEBS and UL 1950 compliance
• Industry leading 10-year warranty
Functional Description
The Total Access 850 System comprises the chassis,
common cards, and access modules. Associated with
the system are additional elements including an AC to
DC power supply and battery charging unit and a bat-
tery pack for backup power.
External AC and DC Power.
The ADTRAN AC/DC
Power Supply/Battery Charging unit receives its
power from a standard 115 VAC outlet. The PSU
supplies a constant -48 VDC to the voice cards. The
power supply battery charging circuit maintains the
battery pack at peak charge. In the event of an AC
power failure, the battery backup circuit automatically
provides battery power to the PSU for up to 8 hours.
When AC power is restored, input power automatically
returns to the AC supply and the battery charging
circuit will recharge the battery to peak.
On the Total Access 850 chassis, the incoming power
termination point is on either of two backplane
connections: P7 or P6. (See Figure 2.) Both sources
connect
directly to the PSU. Connector P6 is used when the
chassis is powered by the ADTRAN AC/DC Power
Supply unit (P/N 1175043L2) which mounts externally
to the chassis. Connector P7 is used when -48 VDC is
available on site and screw-type terminal connections
are required.
Figure 2. Total Access 850 Backplane
PSU.
The Power Supply Unit supplies -48 VDC and
20 Hz ringing voltage to the RCU, BCUs, and access
modules. The PSU converts -48 VDC input to the
required voltages needed to operate all common units
and access modules. The ring generator circuit provides
20 Hz ring voltage to the analog access modules.
The PSU faceplate (see Figure 1 on page 1) shows the
following: a ring enable button, a power LED, a ring
LED, a bank alarm LED, and an alarm cutoff (ACO)
pushbutton switch. The separately fused ring generator
supplies up to 20 REN to the access modules.
BCU.
The Bank Controller Unit is a common module
plug-in unit with a built-in CSU. The BCU provides all
control functions for the Total Access 850 common units
and all individual access modules. A faceplate
ADMIN
DB-9 provides access for a VT 100 terminal for screen
menu provisioning, and bantam test jacks provide
transmit and receive monitoring. An additional
TEST
DB-9 provides timing for DS0 test equipment. Faceplate
LEDs show status information for the network and
Fractional (DSX-1) T1 (L2 only). The unit consists of a
main circuit board and daughter card and inserts
directly in the controller slot on the Total Access 850
shelf. An 8-position DIP switch is mounted on the
daughter card and is used for T1 provisioning and
clocking.
RCU.
The Router Control Unit is a dual board assembly
that provides the network interface. The RCU can
provision, test, and provide status for any card in the
channel bank. A faceplate
CRAFT
DB-9 provides access
for a VT 100 terminal for screen menu provisioning, and
bantam test jacks provide transmit and receive
monitoring. Faceplate LEDs show status information
for the network, V.35, and Ethernet ports.
WARNING
On Total Access 850 installations that do not use
all chassis slots, UL 1950/NEBS requires that the
empty slots must have a Total Access 850 blank unit
(part number 1175099L1) installed in the opening.
