1558A APS
3-6
Operation
3.3.5
Status Indicators
The 1558A front panel STATUS A and B LEDs (amber)
indicate which of the two T1 receive paths (A or B) is pres-
ently being utilized to provide service to the CPE equip-
ment.
3.3.6
Manual Path Selector Switch
The front panel manual PATH SELECT switch is used to
force the 1558A to use either the A or B path as the active
line. If the user momentarily moves the switch to either the
A or B position and then returns the switch to the normal/
center position, the 1558A will force service to the selected
path (A or B). If the user leaves the switch in the manual A
or B position, the 1558A will LOCK the service to this path
and turn on the LOCKED LED.
3.3.7
Path Status Alarm Indicators
The 1558A alarm circuitry is driven by the alarm parameters
defined by the user at time of installation. The user definable
alarm parameters are ES (errored seconds), CSES (consecu-
tively errored seconds), LOS (loss of signal), LOF (consecu-
tively ESF errored frames). When any of these alarm
thresholds are met or exceeded, the ALARM LED indicator
(red) will be on for the path (A or B) that has “failed”.
3.3.8
Path Status LOS Indicators
The 1558A LOS (loss of signal) Path A and B indicators
(amber) will be ON when no T1 pulses are being detected
on the receive signal paths from the network. The definition
of loss of signal is no pulses for 175 bit times. The loss of
signal state will be cleared when one or more data pulses are
detected on the receive path. After the pulses are detected,
the respective LOS indicator will be turned OFF.
3.3.9
Path Status Loop Indicators
The 1558A can respond to CSU loop commands (both
inband and FDL) and local or remote APS loop commands.
When a loop has been activated (Path A, B, or DTE) the
respective front panel LP LED indicator (amber) will be
ON. If no loop is active, the LP indicator will be OFF.
3.3.10 Bantam Test Access Jacks
Bantam test access jacks and bridge/monitor jacks are pro-
vided to gain physical access to the T1 Path A (NET A), T1
Path B (NET B), and the T1 DTE path. The placement of
the jacks is depicted in
Figure 4-2 on page 4-11
. The func-
tion of these jacks is described in the following table.
3.3.11 DTE Loop Indicator
The 1558A DTE port can be looped either locally or
remotely by receipt of soft commands generated either from
the LAPS software interface or from a far end unit. When a
loop has been activated, the front panel DTE LP indicator
(amber) will be ON. If no loop is active, the DTE LP indica-
tor will be OFF. Note that a DTE loop interrupts service.
3.3.12 DTE LOS Indicator
The 1558A LOS (loss of signal) DTE port indicator (amber)
will be ON when no T1 pulses are being detected on the
receive path from the CPE equipment. A loss of signal con-
Path A /B Jacks
Function
Transmit (TX) to T1
facility (upper left
jack)
Allows the user to gain access to the trans-
mit T1 path towards the T1 facility. Insert-
ing a test cord into this jacks disconnects
the 1558A from the T1 facility
Receive (RX) from
T1 facility (lower
left jack)
Allows the user to gain access to the
receive T1 path from the T1 facility.
Inserting a test cord into this jacks discon-
nects the 1558A from the T1 facility
Transmit Bridge
(BRDG) to T1 facil-
ity (upper right
jack)
Allows the user to bridge/monitor the
transmit T1 signal towards the T1 facility.
Note, test set must be set to the bridge ter-
mination mode.
Receive Bridge
(BRDG) from T1
facility (lower right
jack)
Allows the user to bridge/monitor the
receive T1 signal from the T1 facility. Test
set must be set to the bridge termination
mode.
DTE Jacks
Function
Transmit (TX) into
the 1558A from the
DTE equipment
(upper left jack)
Allows the user to gain access to the trans-
mit T1 path from the DTE into the 1558A.
Inserting a test cord into this jacks discon-
nects the 1558A from the DTE equipment
Receive (RX) from
the 1558A to the
DTE equipment.
(lower left jack)
Allows the user to gain access to the trans-
mit T1 path from the 1558A to the DTE
equipment. Inserting a test cord into this
jacks disconnects the 1558A from the
DTE equipment
Transmit Bridge
(BRDG) to T1 facil-
ity (upper right
jack)
Allows the user to bridge/monitor the
transmit T1 signal coming from the DTE
equipment.Note, test set must be set to the
bridge termination mode.
Receive Bridge
(BRDG) to DTE
equipment.(lower
right jack)
Allows the user to bridge/monitor the
receive T1 signal coming from the 1558A
to the DTE equipment.Note, test set must
be set to the bridge termination mode.
