Section 150-611-103
Revision 01
Page 16
TABLE 4. HLU-611 TEST PROCEDURES FOR A1LB OPTION (CONTINUED)
Step
Action
5
Using the following codes, a NETWORK tester can activate loopbacks NLOC or NREM or SMJK (if
enabled) shown in Figure 5. A CUSTOMER tester can activate loopbacks CLOC or CREM.
Addressable 1 (A1LB) Repeater Loopback Commands
ARMING or NIU LPBK (inband)
Arming code
11000 11000..
ARMING or NIU LPBK (ESF Data Link)
Arming code
1111(F)*1111(F)0100(4)1000(8)
IR LPDN or DISARM (inband)
Disarming code
11100 11100..
DISARM (ESF Data Link)
Disarming code
1111(F)1111(F)0010(2)0100(4)
IOR LPBK (NLOC & CREM 231 errors)
HLU Loop up
1101(D)0011(3)1101(D)0011(3)
ILR-2 LPBK (NREM & NLOC 20 bit errors)
HRU Loop up
1100(C)0111(7)0100(4)0010(2)
IR LPDN
Loop down (HLU or HRU)
1001(9)0011(3)1001(9)0011(3)
IR QUERY LPBK
Query loopback
1101(D)0101(5)1101(D)0101(5)
IR ALTERNATE QUERY LPBK
Alternate Query loopback
1101(D)0101(5)1110(E)1010(A)
TIME-OUT OVERRIDE
Loopback Time-out Override
1101(D)0101(5)1101(D)0110(6)
FAR END NIU ACTIVATE
Unblock AIS & pass 2 in 5
1100(C)0101(5)0101(5)0100(4)
IOR POWER DOWN (HLU)
Removes VHDSL line power
0110(6)0111(7)0110(6)0111(7)
Note: the left most bit arrives first in all 8 sequences. The detection algorithm functions reliably with a
random 10E-3 bit error ratio (BER) on the facility. The IOR POWER DOWN code must remain present
for the duration of the power down mode. When this code is removed, HiGain-2 returns to its normal
unlooped and unarmed state.* This is the HEX number for the 4 bit group.
6
After testing is complete, send the universal loopdown [IR (Intelligent Repeater) LPDN] code if the
system is to loopdown but remain ARMED. Send the disarm code 11100 if all the equipment is to be
looped down, disarmed and returned to normal operation. Note that the ARMED mode has an
automatic time-out of 120 minutes.
7
The NREM and NLOC loopbacks can also be initiated from the front panel of the HLU with the MODE
and SEL pushbuttons. See Paragraph 7.20 for details.
