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Section 150-319-254
Revision 02

Page 24

3.  LOOPBACK DESIGN DESCRIPTION

3.01

All HiGain ELU/ERU system loop-up codes 
must be initiated from either the front panel

pushbuttons or from the maintenance terminal.  The
HiGain E1 system does not respond to any 

in-band

codes.

3.02

Two additional loopback points are added

for 

each EDU-451 doubler that is used as

shown in Figure 14.  NDU1 and NDU2 are executed
towards the network.  CDU1 and CDU2 are towards
the customer.  NDU1 and NDU2, along with the rest
of the loopbacks towards the network, can be issued
from the Loopback Menu shown in Figure 22.

3.03

Depressing both the MODE and SEL push-
buttons on the front panel for at least three

seconds initiates a MANUAL loopback session.  This
session allows the user to SEL one of eight HiGain
system loopbacks.  The message, “MAN LPBK”,
appears on the front panel display followed by the
message “NLO?”  If the SEL push-button is now
pressed, an “NLOC” loopback is executed and the
message changes from “NLO?” to “NLOC”.  If the
MODE button is pressed instead of the SEL push-
button, “NLO?” is replaced by “ND1?”.  This now
allows an ‘NDU1’ loopback to be executed (if it is a
Doubler application) with the SEL push-button.  If
this same routine is followed, all eight loopbacks
(NLOC, NDU1, NDU2, NREM, CLOC, CDU2, CDU1
and CREM) are presented and can be initiated in the
sequence listed. Pressing the MODE push-button
two more times yields the CRE and CLO loopback
options in the sequence listed.  This interactive
push-button procedure  permits any of the eight
HiGain loopbacks to be executed/activated.  The

next loopback option is presented by pressing the
MODE push-button however, the previously
executed loopback will remain active until the SEL
push-button is pressed and a different loopback is
activated.  If neither button is pressed for a period of
30 seconds and no loopback is in effect, the manual
loopback session terminates and the normal margin
displays reappear.  If any loopback is in effect, the
30-second time-out is inhibited.  The active loopback
and the manual loopback session continue until the
loopback times out in accordance with the user
selected LBTO setting.  Only one loopback can exist
at any given time.  Pressing both buttons again for
three seconds, terminates any active loopback, ends
the MANUAL loopback session and returns the
display to normal mode.

3.04

Note that these loopbacks can be
initiated from the RS-232 maintenance port

by choosing LOOPBACK MODE, option D, from the
main menu.  This displays the Loopback Menu,
shown in Figure 22  from which you can initiate any
of the six loopbacks for this single doubler
application.

3.05

If the system should ever fail to respond to 
any loopback command, go to the front

panel Option Setting mode and execute the
“DFLT/YES” command described in paragraph 5.05.
This will allow the system to respond to the loopback
commands.  Reset the parameters to their original
non default values, if needed, at your convenience,
after the system resumes its proper response to
loopback commands.

Содержание 150-1236-54

Страница 1: ...ITHOUT USING HIGAIN DOUBLER EDU 451 11 1 GENERAL 11 2 POWER CONSUMPTION 11 3 LOOPBACK DESIGN DESCRIPTION 12 4 TESTING 13 5 SYSTEM MAINTENANCE MENU SCREENS 17 C APPLICATIONS USING HIGAIN DOUBLER EDU 45...

Страница 2: ...s practice Revision 02 February 22 1996 a Numerous updates to tables figures also screen captures to include HiGain Doubler EDU 451 1 03 The ELU 319 is compatible with the PairGain 22 slot HMS 318 she...

Страница 3: ...ting ranges on unimpaired cable pairs are shown in Table 2 as a function of cable gauge and average margin 2 05 The ELU 319 List 5D and 6D line units support both one and two doubler applications For...

Страница 4: ...G 703 clock at the exact rate received from the remote end The HiGain system operates at G 703 rates of 2 048 Mbps with up to 50 ppm of offset 3 07 A G 703 interface driver converts the G 703 channel...

Страница 5: ...at the ELU or ERU G 703 inputs exceeded the 24 hour user selected threshold 7 ALRM MAL1 2 The margin on HDSL Loop 1 Loop 2 has dropped below the Margin Alarm Threshold value set from the Maintenance P...

Страница 6: ...Section 150 319 254 Revision 02 Page 6 Figure 3 ELU 319 Pin Outs The active pins are highlighted in black in this illustration...

Страница 7: ...after initiation 60 Sets automatic cancellation of all loopbacks to 60 minutes after initiation 120 Sets automatic cancellation of all loopbacks to 120 minutes after initiation ALM Minor Alarm DIS Ret...

Страница 8: ...rns to normal display mode If you do not press either button within 30 seconds the parameters return to their original values and the display returns to normal mode 5 05 To set all parameters to their...

Страница 9: ...it board as shown in Figure 5 6 02 The factory default setting is unipolar It sets the HDSL line voltage to 0 V on loop 2 and to either 130 V for non doubler applications or 200 V for doubler applicat...

Страница 10: ...Line Code 1040 kbps 2B1Q HDSL Output 13 5 dBm 0 5 dB 135 ohms HDSL Line Impedance 135 ohms Line Clock Rate Internal Stratum 4 clock HDSL Startup Time 30 seconds typical 60 seconds maximum One way G 70...

Страница 11: ...tive unit freight prepaid along with a brief description of the problem to PairGain Technologies Inc 14402 Franklin Avenue Tustin CA 92680 ATTN Repair and Return Dept 714 832 9922 800 638 0031 11 TECH...

Страница 12: ...a MANUAL loopback session This session allows the user to SEL one of four HiGain loopbacks see Figure 5 The message MAN LPBK appears on the front panel display followed by the message NLO If the SEL b...

Страница 13: ...r to conserve power the display de energizes after five minutes if neither MODE or SEL are pressed The use of either button restarts the 5 minute power control timer 4 02 If you encounter trouble with...

Страница 14: ...1 ACQ 1 or 2 Acquisition 1 or Acquisition 2 The ELU and ERU multiplexers are trying to establish synchronization over each of Loops 1 or 2 of Span 1 H1ES HDSL Loop 1 errored second HDSL CRC error on...

Страница 15: ...review mode Press the Mode button for 3 seconds LIST 000X ELU s List Displayed during System Settings review mode defined above LOSW Loss of Sync Word Indicates that one of the HDSL loops has lost sy...

Страница 16: ...Off AM Alarm cut off is in effect LAIS Local Alarm Indicating Signal Indicates an AIS all 1 s pattern is being transmitted from the local G 703 output port RAIS Remote Alarm Indicating Signal Indicate...

Страница 17: ...conds ES The number of seconds during which at least 1 bipolar violation was detected at the G 703 input G 703 UAS Count The number of seconds during which the G 703 input signal was absent 125 or mor...

Страница 18: ...703 inputs are listed for the current and previous seven days All of the counters can be set to zero by pressing C Clear on the SPAN STATUS Screen Figure 7 Note that since the ELU is considered the m...

Страница 19: ...Section 150 319 254 Revision 02 Page 19 Figure 6 Main Menu Figure 7 Span Status Display no Doubler...

Страница 20: ...Section 150 319 254 Revision 02 Page 20 Figure 8 Set Clock Menu Figure 9 System Settings Menu...

Страница 21: ...Section 150 319 254 Revision 02 Page 21 Figure 10 Loopback Menu no Doubler Figure 11 Performance Data Display no Doubler...

Страница 22: ...Section 150 319 254 Revision 02 Page 22 Figure 12 Performance Data History Display no Doubler Figure 13 Alarm History no Doubler...

Страница 23: ...on density in Watts sq ft 2 03 The thermal loading limitations imposed when using the ELU 319 in Controlled Environmental Vaults CEV or other enclosures are determined by applying the ELU 319 power pa...

Страница 24: ...d CLO loopback options in the sequence listed This interactive push button procedure permits any of the eight HiGain loopbacks to be executed activated The next loopback option is presented by pressin...

Страница 25: ...Section 150 319 254 Revision 02 Page 25 Figure 14 ELU 319 Doubler Loopback Configurations Each module four in a full two doubler system can be looped back toward either the network or customer...

Страница 26: ...buttons or maintenance terminal Figure 14 HDU2 Network Doubler 2 Loopback Loopback at Doubler 2 towards network initiated by ELU 319 front panel MANUAL LOOPBACK push buttons or maintenance terminal Fi...

Страница 27: ...r alarm MNRALM condition is in effect 1 xx or 2 yy HDSL Loop Margins Indicates the worst case signal to noise ratio measured for each loop A value of 06 or greater is adequate for reliable system oper...

Страница 28: ...hreshold 1 to 15 Setting the threshold to 0 zero inhibits the alarm ACO Alarm Cut Off Al Alarm cut off is in effect LAIS Local Alarm Indicating Signal Indicates an AIS all 1 s pattern is being transmi...

Страница 29: ...MANUAL LOOPBACK push buttons or maintenance terminal Figure 14 CLOC Customer Local Loopback Loopback at ERU 412 local towards customer interface CI initiated from the maintenance terminal or by press...

Страница 30: ...er of seconds during which the G 703 input signal was absent 125 or more consecutive zeroes ELU Ver x x yyyy ERU ver x x yyyy x x the software version number of the ELU 319 or ERU 412 yyyy the list nu...

Страница 31: ...e cleared 5 08 Figure 27 through Figure 30 show the 7 DAY PERFORMANCE HISTORY screens for Doubler applications The Errored Seconds and Unavailable Seconds for both HDSL loops and each of the two G 703...

Страница 32: ...Section 150 319 254 Revision 02 Page 32 Figure 15 Main Menu Figure 16 Span Status Display no Doublers...

Страница 33: ...Section 150 319 254 Revision 02 Page 33 Figure 17 Span 1 Status Display one or two Doublers Figure 18 Span 2 Status Display two Doublers...

Страница 34: ...Section 150 319 254 Revision 02 Page 34 Figure 19 Span 3 Status Display two Doublers Figure 20 Set Clock Menu...

Страница 35: ...Section 150 319 254 Revision 02 Page 35 Figure 21 System Settings Menu Figure 22 Loopback Menu one Doubler...

Страница 36: ...Section 150 319 254 Revision 02 Page 36 Figure 23 Performance Data Span 1 Figure 24 Performance Data Span 2...

Страница 37: ...Section 150 319 254 Revision 02 Page 37 Figure 25 Performance Data Span 3 Figure 26 Performance History Span 1...

Страница 38: ...Section 150 319 254 Revision 02 Page 38 Figure 27 Performance History Span 2 Figure 28 Performance History Span 3...

Страница 39: ...Section 150 319 254 Revision 02 Page 39 Figure 29 Alarm History Span 1 Figure 30 Alarm History Span 2...

Страница 40: ...150 319 254 Revision 02 Page 40 Figure 31 Alarm History Span 3 Copyright 1996 PairGain Technologies Inc PairGain is a registered trademark CopperOptics and HiGain are trademarks of PairGain Technolog...

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