61179512L2-5A
Section 61179512L2-5, Issue 1
7
Table 4. Loop Insertion Loss Data
FrequencyMaximum Loss
(Hz)
(dB)
3,000 .............................................. 12.00
10,000 ............................................ 15.00
50,000 ............................................ 25.50
100,000 .......................................... 30.00
150,000 .......................................... 32.75
196,000 .......................................... 35.00
200,000 .......................................... 35.25
250,000 .......................................... 37.50
300,000 .......................................... 42.00
Table 3. HDSL Loss Values
(200 kHz cable loss in dB/kft at 135
Ω
)
Cable Gauge
26
26
24
24
22
22
19
19
Cable Type
PIC
Pulp
PIC
Pulp
PIC
Pulp
PIC
Pulp
Temperature
68
°
90
°
120
°
3.902
4.051
4.253
4.030
4.179
4.381
2.863
2.957
2.083
3.159
3.257
3.391
2.198
2.255
2.333
2.483
2.450
2.629
1.551
1.587
1.634
1.817
1.856
1.909
Table 5. ICOT Troubleshooting Guide
Solution
1. Make sure the ICOT is properly seated in the housing.
2. Verify that the ICOT is delivering sufficient simplex voltage to the loops, if line powered.
3. If steps 1 and 2 pass, replace the ICOT.
1. Verify that the loop conforms with CSA guidelines (not too long, etc.).
2. Verify that the tip and ring of each HDSL loop belong to the same twisted pair.
3. Verify that loop loss at 200 kHz is not greater than 35.25 dB.
4. Verify that noise on both HDSL loops is within acceptable limits.
5. If steps 1 through 4 pass and loop sync is still not available, replace the unit with one known
to be in proper working condition.
Condition
All front panel indicators are
Off
.
Power is present and adequate, but
loop sync is not available (LP1
and/or LP2 LEDs are
Off
).
Figure 9. CSA Deployment Guidelines
0
12
11
10
9
8
7
6
5
4
3
2
1
0
1
2
3
4
WORKING LENGTH OF 26 GAUGE CABLE (KFT)
WORKING
LENGTH
OF
24
GAUGE
(OR
COARSER)
CABLE
(KFT)
5
6
7
8
9
2.5
2.0
1.5
1.0
0.5
0.0
TOTAL
BRIDGED
TAP
LENGTH
(KFT)
VALID CSA CABLE LENGTHS
INVALID CSA CABLE LENGTHS
Loop loss per kft for other wire is summarized in
Table 3
.
Recommended maximum local loop loss information
for PIC cable at 70
°
F, 135
Ω
resistive termination is
provided in
Table 4
.
An approximation for the maximum amount of
wideband noise on an HDSL local loop as measured
by a 50 kb filter is -31 dBrn.
An approximation for the maximum level of impulse
noise as measured using a 50 kb filter on an HDSL
loop is -50 dBrn.
NOTE
These approximations are to be used as guidelines
only and may vary slightly on different loops.
Adhering to the guidelines should produce
performance in excess of 10
-7
BER.
6. ICOT TROUBLESHOOTING PROCEDURES
Use
Table 5
to troubleshoot the ADTRAN Total
Access ICOT.
