ACS-160 Series & STL-160 Series T1 Mux Installation & Operation 6-Testing & Troubleshooting
Version 2.11, August 2011
6-10 Harris Corporation
Intraplex Products
• Create an external loopback by connecting a Bantam-Bantam patch cord from the T1 OUT
EQUIP jack to the T1 IN EQUIP jack.
• Create an internal equipment loopback by using the GROUP and SET/NEXT switches to
activate the EqLB function (Section 6.3.1).
6. Unseat all the channel modules in the multiplexer by pulling on their eject tabs but do not remove
them completely from the shelf. With no channel modules active, the T1 transmitter produces an
all-ones signal, which is looped back to the T1 receiver.
7. Verify that the indicator lights respond (Table 6-6).
8. Press all the channel modules firmly back into their sockets.
9. Perform one or more channel tests using available VF, data, and other type test sets. These tests
might include level tests on voice channels, bit error tests on data channels, and so on (Figure 6-
9).
Note: At this stage, you can perform channel tests only on 4-wire voice channels or full-duplex
data channels.
10. When channel tests are complete, take down the loopback either by removing the patch cord or by
deactivating the equipment loopback.
11. In a field test only – If the network configuration requires this multiplexer to use a timing source
other than internal, perform these steps to reset the timing source:
a. Press down repeatedly on the GROUP switch until the display shows TIME.
b. Press down repeatedly on the SET/NEXT switch until the display shows the desired timing
source (LOOP or EXT).
c. Press up twice on the SET/NEXT switch to reset transmit timing to the source currently
displayed.
12. Reconnect the T1 input/output connector (RJ-48C) to the MA-215 module adapter at the rear of
the CM-5RB module (or DB-15 on the MA-216 adapter).
Table 6-6. Indicator Lights in Terminal Multiplexer Loopback Test
CM-5RB Module
Indicator
Patch Cord
Loopback
EqLB
Loopback
TX OUT ON ON
RX IN BLINKS OFF*
ERR OFF OFF
YEL OFF OFF
BPV OFF OFF
AIS OFF OFF
FRM OFF OFF
INT ON ON
LPBK OFF ON**
CPU OFF OFF
NORMAL ON OFF
ALERT OFF** ON**
ALARM OFF OFF
* The RX IN light blinks to indicate detection of an all-ones signal. With an internal (EqLB) loopback
active, no signal reaches the T1 receiver.