Specifications

Reference Guide
2-3
Applications Voice Modules and Applications
Test functionality also includes the ability to generate test tones (300Hz, 1 kHz, 3 kHz and
"quiet") and transmit those toward either the user side or the network side of the system. FXS
cards can use the voice-compression features of the ADPCM and LBRV resource cards.
2.3.2 Foreign Exchange Office (FXO) Card
This integrated access system supports one variant of Foreign Exchange Office (FXO) cards:
•
8139 FXO Card provides eight 2-wire analog ports with terminating impedance of 600
ohms.
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 Ringing 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).
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).
As described above, 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. The PCM Coding options supported
include "
µ
-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 600_@2.15µF in the case of
the Model 8139 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. It also sets and monitors the state of
the digitized voice signal’s ABCD signaling bits In cross-connect systems, the Test
functionality also includes the ability to generate test tones (300Hz, 1 kHz, 3 kHz and "quiet")
and transmit those toward either the user side or the network side of the system.