CopperOptics 150-1141-24, Manual

Page: 22 / 66

Section 150-388-124
Revision 01
Page 22
TABLE 5. HLU-388 A3LB TEST PROCEDURES
Step Action
1 The HiGain Line Unit can be looped back (NLOC in Figure 6) by sending the Addressable Office
Repeater (AOR) LPBK activation code 1111 1111 0001 1110 (FF1E) for at least five seconds. This
causes the HLU-388, List 2D to enter its NLOC state (see Figure 6). The display on the HLU-388, List
2D alternates between NLOC (network local loop) and the margin displays. The Loopback Time-out
option (which is user settable to “None,” 20, 60, or 120 minutes) determines the duration of this
loopback, unless it is overridden by the reception of a second identical 16-bit loop-up command before
the timer expires. When this time-out override state exists, the only way to loop the HLU-388, List 2D
down is to issue one of the three loop-down commands listed in Step 2. The automatic time-out mode is
restored during subsequent loopback sessions.
2 The following list summarizes the codes required to execute all the HiGain loopbacks (see Figure 6).
Note that all code sequences must be present for at least five seconds.
ABBREVIATIONS USED BELOW:
LU = Loop Up
LD = Loop Down
NI = Network Interface
CI = Customer Interface
ESF-DL = Extended Super Frame Data Link
ADDRESSABLE 3 (A3LB) REPEATER LOOPBACK COMMANDS
Position Name Code
HLU-388 LU from NI NLOC 1111 1111 0001 1110 (FF1E)*
HLU-388 LU from CI CREM 0011 1111 0001 1110 (3F1E)
HRU-412 LU from NI NREM 1111 1111 0000 0010 (FF02)
HRU-412 LU from CI CLOC 0011 1111 0000 0010 (3F02)
HRU-412 LU from NI SMJK 11000 11000 11000 ...
HRU-412 LU from NI SMJK 100000 100000 100000 ...
HRU-412 LU from NI (ESF-DL) SMJK 1111 1111 0100 1000 (FF48)
HLU and HRU LD from NI or CI Loop Down 11100 11100 11100 ...
HLU and HRU LD from NI or CI Loop Down 100 100 100 ...
HLU and HRU LD from NI or CI
(ESF-DL)
Loop Down 1111 1111 0010 0100 (FF24)
Note:
The left-most bit arrives first in all sequences. The detection algorithm functions reliably with a
random 10
-3
Bit Error Ratio (BER) on the facility.
3 All of the above loopbacks can also be initiated from the front panel of the HLU-388, List 2D with the
Mode and SEL push buttons (see Section B Paragraph 14.09). *This is the HEX number for the 16 bit
group.