Toshiba Strata DK 280 Installation Manual page 635

cables that comply with Ti span specifications for
connecting the CSU to customer premise equipment
(like DK280, RDTU) and to the Network Interface
equipment.
11.6 RDTU Loop Back Testing
The RDTU provides three loop back te.st
configurations. These loop back tests should be
performed as required in conjunction with CSU loop
back tests (see CSU loop back test documentation).
11.6.1 RDTU Self Test
This test should be performed upon initial installation
of a RDTU PCB. Program the RDTU per Section 11.4
of this section; then perform the RDTU loop back test,
per the instructions in Figure 11-7, before connecting
the far end (CSU, Network, or CPE) Tl span line.
11.6.2 Network/CSU Tl Span Test
This test will verify that the far end (CSU, Network, or
CPE) Tl equipment and span cabling is functioning
properly. This test checks all Tl span cabling including
the RDTU amphenol cable and connector. Guidelines
for this test are provided in Figure 11-8.
11.6.3 Network/CSU/RDTU Span Test
This test checks all equipment that is checked with the
test in the above paragraph, but this test also checks
RDTU SELF CHECK
1
MM8976B
that the RDTU Mite1 LSI chip is functioning. Guidelines
for this test are described in Figure 11-9.
Note:
Loop back tests shown in Figures 11-7,
11-8, and I l-9 show loop back testing with
CSlJ and Network equipment. The same tests
can be performed when connecting the RDTU
PC9 directly to a customer premise (PBX,
Key Hybrid, Channel bank) Tl circuit.
RDTU Self Check
n Active test of RDTU circuit.
Network/CSU Test
W Tests all cables, Network and CSU equipment
(RDTU is not active).
Remote Loop Back (RLB) Test
W Active test of RDTU (LSI MM8976B), CSU,
Network equipment and all cables.
CSU Local/Network Loopback Tests
n See Figure 11-10 and the CSU manufacturer's
Installation and Maintenance manual.
REMOVE NDTU CABLE
a
+T \ _
P2
MI-TEL CHIP
1
DK0516
General Notes:
l
Pl and P2 to ON position (see Figure 1 l-5).
l
Remove NDTU cable from RDTU amphenol connector.
l
After about 12 seconds, all RDTU LEDs (except PRI/SEC SYNC) turn off.
l
Appropriate primary or secondary sync. LED flashes if RDTU is Primary or Secondary reference.
l
If RDTU is not a primary or secondary reference, then the Primary and Secondary sync LEDs
should turn off.
Figure
11-7
RDTU Self Test
January
1996
11-11