AMERITECH AM8a, Instruction Manual

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AM8a Instruction Manual (18-0037) Front Panel Operation
0037-S01.L_19 February 10, 2000
1-9
1.4 CONTROL ON/OFF KEYS
Additional control of configuration on the AM8a is available through
ON/OFF
function keys
on the lower left of the front panel. (See Figure 1-1.) The green LED indicates when the
function is
ON
. The following descriptions review the specific configuration control
provided:
1.4.1
INPUT ([SHIFT][*, KP]) Key:
This key controls the AM8a connection to the selected line
being emulated or monitored. Connections are described in Section 6 along with
metering of circuits.
•
ON
: the test set has full access to the lines selected; this is the standard condition.
•
OFF
: all AM8a interfaces to the line jacks change to high impedance or open
circuits that will not interfere with the line under test.
NOTE:
The
OFF
position is a built-in safety feature that prevents glitches during
any rearrangement of the external connections during AM8a configuration
changes. In addition, if certain trunk configuration parameters are
changed,
INPUT
is forced
OFF
.
1.4.2
TIMS ([SHIFT][#, ST]) Key:
This key controls connection of a Transmission Impairment
Measurement Set (a
TIMS
such as the Ameritec AM5XT) to test the transmission
quality of the line. The
TIMS
is connected to the
TIMS
jacks on the front panel. The
key provides a three-position toggle.
NOTE:
For
PCM1
or
PCM2
, the
TIMS
jacks are connected internally to the selected
CHAN
nel. Refer to the Appendix that describes
PCM
operation.
•
1 (green LED ON): When on, the
TX
and
RX
circuitry in the AM8a is connected to
the
TIMS 2W/TX
and
RX
jacks. For
2W
circuits or analog
LOOP
, the
TIMS 2W/TX
jack is used. For
4W
circuits, both jacks are used.
•
2 (green LED flashes): When in a monitor
PCM
mode, the
TIMS
jack
RX
and
TX/2W
connections to the AM8a circuitry are reversed.
•
3 (green LED OFF): The
TIMS
jacks are Open and there is no connection to the
AM8a circuitry.