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Reference Guide 4-3
Applications Voice Modules
4.2.2 Foreign Exchange Office (FXO) Card (8000-FXO-8P)
This Integrated Access System supports three variants of Foreign Exchange Office (FXO)
cards:
• 8000-FXO-8P Card provides eight 2-wire analog ports with terminating impedance of
600 ohms with improved ground-start signaling.
FXO cards can be installed in any of the User Slots of the system chassis. FXO cards encode
the incoming analog voice signals into 64 Kbps PCM format before transmission onto the
network.
A Ring Generator is required if one or more FXO ports in a system are programmed to operate
in Manual Ringdown (MRD) mode.
In addition, a physical jumper must be set on the FXO card for each port programmed for
MRD operation. Each FXO card provides a single 50-pin female AMPHENOL connector
(RJ27X).
The MRD mode also requires the setting of physical jumpers. The Signal setting specifies
Loop Start, Loop Forward, Ground Start, R2, and Immediate R2 operation. In "fxodn" and
"dpt" modes, the user may also specify the wink duration time and wink delay from 0.1
seconds to 9.9 seconds in 0.1 second increments.
All port parameters are software configurable on a port by port basis. The Mode setting
specifies whether the port is to be used for standard Foreign Exchange Office, Foreign
Exchange Software Defined Network, Dial Pulse Terminate, or Manual Ring Down (MRD).
The PCM Coding options supported include "mu-law", "A-law" and inverted A-law. The user
may select the Trunk Conditioning mode ("busy" or "idle") that should be applied towards the
attached equipment should the WAN facility that the port is connected to fail. In addition, both
the Transmit (Tx) and Receive (Rx) TLP levels can be set in increments of 0.1 dB. The Tx
TLP range is from -10.0 dB to +5.0 dB. The Rx TLP range is from -10.0 dB to +2.0 dB.
The user may also specify, on a port-by-port basis, whether to use North American ANSI
standard ABCD signaling (which is the default) or ITU (CCITT) ABCD signaling by turning
the signaling conversion setting "on" or "off."
The trans-hybrid balance may be specified as one of eight values (known as "set1" through
"set8") as well as for a customized user-specified terminating impedance ("user"). All eight
values are identical and are set for a terminating impedance of 600Ohms @ 2.15µF in the case
of the Model FXO-8P FXO cards.
Software-initiated testing and diagnostics supported on FXO cards include the setting of both
analog and digital loop backs towards the network and generating a Digital MilliWatt signal
on a port-by-port basis. A robust set of Test functions allow the user to monitor and set the
state of the analog Tip and Ring leads of any FXO port.