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Troubleshooting

 150-231-181-01, Revision 01

46

September 7, 1999

 HLU-231 List 8A

Initiating a Manual Loopback Session

A manual loopback session allows you to select any one of the HiGain GNLB loopbacks listed in 

Table 13 on 

page 44

 with the exception of SmartJack loopbacks, which can only be issued by inband commands. 

Setting the Loopback Time-out Option

Before initiating a loopback session, verify that the Loopback Time-out parameter is set to the desired setting. 

1

Use the MODE and SEL buttons as described in 

“Setting Options through MODE and SEL” on page 11

(The Loopback Time-out parameter is also user-selectable from the System Settings screen when using a 
maintenance terminal.)

2

Enter the desired setting:

NONE (no time-out)

20 minutes

60 minutes (default setting)

120 minutes

Initiating a Manual Loopback Session

To initiate a manual loopback session:

1

Press both the MODE and SEL buttons on the front panel for at least 3 seconds. The following message 
appears on the front-panel display:

MAN LPBK NLO?

2

Press SEL to activate NLOC. 

3

The following message appears: 

Perform selected loopback

 

(

 

or

 

)

?

4

Type 

. The display changes to 

MAN LPBK NLOC

.

5

Press MODE to advance to the next available loopback (ND1? ND2? ND3? ND4? NRE? CRE? CD1? CD2? 
CD3? CD4? CLO?).

6

Press SEL to activate the selected loopback. The previous loopback is terminated.

With the exception of SmartJack, any of the HiGain loopbacks can be executed using the MODE 
and SEL buttons. 

When executing a manual loopback session using the MODE and SEL buttons:

The next loopback option can be presented by pressing the MODE button, however, the 
previously activated loopback remains active until the SEL button is pressed, which 
activates the new loopback. 

If neither button is pressed for a period of 30 seconds and no loopback is in effect, the 
manual loopback session terminates and the display returns to normal mode. 

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 LBTO 
setting. 

Only the SMJK loopback can exist with another network loopback at any given time. In 
general, it is preferable to have only one active loopback.

If there is an active loopback, pressing the MODE and SEL buttons for 3 or more seconds 
terminates any active loopback, ends the manual loopback session and returns the display 
to normal mode. 

Y

N

Y

Summary of Contents for T1L2PY0AA

Page 1: ...HIGAIN LINE UNIT PAIRGAIN TECHNOLOGIES INC ENGINEERING SERVICES TECHNICAL PRACTICE 150 231 181 01 Model List Number Part Number CLEI Code HLU 231 8A 150 1111 81 T1L2PY0AA...

Page 2: ...es Inc and shall not be modified used copied reproduced or disclosed in whole or in part without the written consent of PairGain Information furnished by PairGain Technologies is believed to be accura...

Page 3: ...in the subject area of the email message INSPECTING THE SHIPMENT Upon receipt of the equipment Unpack each container and inspect the contents for signs of damage If the equipment has been damaged in t...

Page 4: ...Inspecting the Shipment 150 231 181 01 Revision 01 iv September 7 1999 HLU 231 List 8A...

Page 5: ...th a Downstream Device 9 Provisioning Requirements 10 Provisioning_________________________________________________________________________ 11 Using the MODE and SEL Buttons 11 Setting Options through...

Page 6: ...ns 30 View Performance History Screen 31 Performance History Screen without Doubler 31 Performance History Screen for Doubler Applications 32 View Alarm History Screen 33 Alarm History Screen without...

Page 7: ...ain 57 HLU 231 List 8A Card Connector 58 Network Management Control Bus 58 Fuse Alarm 58 System Alarm Relay Output 59 Craft Port 59 Appendix B Functional Operation ____________________________________...

Page 8: ...4 31 Day Performance History Screen No Doubler 31 15 31 Day Performance History Screen Four Doublers Span 5 32 16 Alarm History Screen No Doubler 34 17 Alarm History Screen Four Doublers Span 5 34 18...

Page 9: ...Codes 44 14 Addressable Repeater Loopback Commands A1LB A2LB A5LB 49 15 Addressable Repeater Loopback Commands A3LB and A4LB 52 16 HDSL Loss Over Cables 54 17 Power Parameters No Doubler 54 18 Power P...

Page 10: ...List of Tables 150 231 181 01 Revision 01 x September 7 1999 HLU 231 List 8A...

Page 11: ...w wander Stratum 1 compliant Low line power option 140 Vdc for circuits with a single doubler Selectable Power Feed PWRF modes Auto High and Low Grounded loop detection on High bit rate Digital Subscr...

Page 12: ...rvice on a temporary or permanent basis Provide a means of quickly deploying service in advance of fiber optic transmission systems With a HiGain system service can be provided within hours Fiber opti...

Page 13: ...1 The HRU 411 has an onboard 130 Vdc 8 5 W power supply that can power the 200 mW PCS remote radio ports The line unit recognizes the HRU 411 if CPE POWER switch is set to ON and performs the followin...

Page 14: ...NT PANEL The HLU 231 List 8A front panel is shown in Figure 1 The front panel components are described in Table 1 on page 5 For pinout diagrams of the HLU card edge connector and the craft port refer...

Page 15: ...codes DSX 1 access jacks SPAN Provides splitting jack access to XMT and from RCV the HDSL span at the DSX 1 interface Breaks the XMT and RCV paths to permit test signal insertion and retrieval MON Pro...

Page 16: ...Customer Remote Loopback Signal from customer is looped back to the customer at HLU 231 NDUn Network Doubler n Loopback Query to initiate loopback at doubler n to network where n is the number of the...

Page 17: ...und One of the HDSL loops has been grounded PWR FEED ON Power Feed On Indicates that the HDSL loops are not grounded or shorted PWR FEED OFF Power Feed Off HDSL span power has been turned off by setti...

Page 18: ...e 2 2 Place your thumbs on the HLU 231 front panel and push the HLU 231 into the card edge connector until the retaining latch closes This indicates that the card is properly seated Upon receipt of th...

Page 19: ...municate with downstream devices status LED flashes red One of the following occurs If downstream devices are successfully identified and the HDSL loops synchronize the HLU status LED will be a steady...

Page 20: ...PC to the craft port can handle all provisioning tasks Tasks that you need to complete are 1 Set the time and date see Set Clock Screen on page 19 2 Set the circuit IDs see View System Inventory Scree...

Page 21: ...e front panel display alternately shows the first system parameter and its current setting 2 Press the SEL button to step through all possible settings one at a time of the selected parameter 3 After...

Page 22: ...aying System Parameter Settings To scroll through the current settings of all system parameters press the MODE button for 3 or more seconds The following parameters are displayed HLU software version...

Page 23: ...8 data bits 1 stop bit hardware flow control to OFF 5 Press the several times to initiate the autobaud connection and to initialize the Maintenance Terminal screens Accessing the Maintenance Terminal...

Page 24: ...opbacks at both the network and customer side 26 View Performance Data Provides access to subscreens that allow you to view the Errored Seconds ES and Unavailable Seconds UAS between the HLU and the H...

Page 25: ...eens depend on whether the system includes one two three or four doublers Press from the Maintenance Terminal Main Menu to open the Span Status screen Figure 5 on page 16 If no doubler HDU is present...

Page 26: ...00 00 00 dB INS LOSS 00 00 00 00 dB 24 HOUR ES 00004 00003 00006 00007 seconds 24 HOUR UAS 00014 00013 00000 00001 seconds DS1 STATUS HLU HRU 24 HOUR ES Count 00001 00002 24 HOUR UAS Count 00000 00002...

Page 27: ...kHz loss The normal HiGain ATTN operation range is from 0 to 28 dB INS Loss Indicates the approximate insertion loss of the loops at the HDSL line rate of 196 kHz It is generated by multiplying the p...

Page 28: ...ex DC voltage and Loop 2 is specified to carry the simplex DC voltage SPx indicates that the first occurrence of a reversed span is on Span x where x is the number of the span CLOC Customer Local Loop...

Page 29: ...ress The Update Remote field appears Update the HRU Time and Date The remote unit date and time is set by using this option Do one of the following Press to update the HRU to the same date and time se...

Page 30: ...letter to change that setting Press to set all user options to the factory default values If changes were made press when exiting to confirm or press any other key to ignore changes Press to exit and...

Page 31: ...em to respond to the inband loopback codes of the Wescom Mod 1 addressable repeater A5LB Configures the HiGain system to respond to the inband loopback codes of the Teltrend Mod 1 addressable repeater...

Page 32: ...AIS 2LP Causes the HiGain system to transmit the AIS signal at both the HLU 231 and HRU T1 output ports when both of the HDSL loops are not in sync LOSW 1LP Causes the HiGain system to transmit the AI...

Page 33: ...on the CRCs in each direction of every HDSL loop of each span are also counted and added in with the BPV count to produce a Total Error Count TEC that indicates the integrity of both the T1 and HDSL p...

Page 34: ...all HiGain system loopback tests for all DS1 blocking settings This allows the standard full bandwidth T1 loopback tests to be performed for all DS0 blocking settings If any of the unused DS0 channels...

Page 35: ...his alerts the maintenance personnel of the problem 2LP requires both HDSL loops to be out of sync LOSW before the HAIS signal is transmitted 2LP preserves the integrity of the 12 surviving channels w...

Page 36: ...itional loopback selections appear on the screen Type to exit and return to the previous menu Table 9 lists the HLU 231 Loopback field messages and descriptions If the HLU 231 is used with the HRU 411...

Page 37: ...U NLOC C NETWORK LOOP HRU NREM G CUSTOMER LOOP HLU CREM H CUSTOMER LOOP HRU CLOC E xit LOOPBACK MENU TIME 00 03 33 DATE 08 05 99 CIRCUIT ID A DISABLE LOOPBACKS B NETWORK LOOP HLU NLOC M NETWORK LOOP D...

Page 38: ...Figure 11 NLOC Loopback Mode Reported in the Maintenance Terminal Main Menu Disabling a Loopback The Disable Loopbacks option Figure 9 on page 27 allows you to disable cancel any of the loopbacks lis...

Page 39: ...hour data screen Press to view the next available span for doubler applications Press or to select a specific span for doubler applications Press to exit All Performance Data counters can be set to z...

Page 40: ...U4 to the HRU Invalid report entries are indicated by dashes Figure 13 Performance Data Screen Four Doublers Span 5 Date 08 05 99 PERFORMANCE DATA CIRCUIT ID ERRORED SECONDS UNAVAILABLE SECONDS DS1 HD...

Page 41: ...reen Press to exit from the Performance History screen Performance History Screen without Doubler Figure 14 shows a non doubler application Invalid report entries are indicated by dashes Figure 14 31...

Page 42: ...d report entries are indicated by dashes Figure 15 31 Day Performance History Screen Four Doublers Span 5 Time 00 26 29 SPAN 5 PERFORMANCE HISTORY 31 DAY CIRCUIT ID ERRORED SECONDS UNAVAILABLE SECONDS...

Page 43: ...se descriptions apply to the Alarm History for doubler applications as well Table 11 Alarm History Fields and Descriptions Field Description Type Identifies the type of alarm LOS DS1 HLU First and las...

Page 44: ...DATE 08 05 99 CIRCUIT ID Type First Last Current Count LOS DS1 HLU OK 000 LOS DS1 HRU OK 000 BER OK 000 SPAN1 LOSW HDSL1 02 01 99 00 00 02 01 99 00 00 OK 001 SPAN1 LOSW HDSL2 02 01 99 00 00 02 01 99 0...

Page 45: ...is lost The System Inventory screen displays HiGain unit serial numbers For HLU 231 List 8A units manufactured prior to August 5 1999 the screen displays only the last six digits of the serial number...

Page 46: ...T PRODUCT SERIAL NUMBER UNIT ID HLU HLU 231 L8A V7 1 000004 NOT REQUIRED B HRU HRU 402 L1 V1 5 3499000400 C DB1 N A D DB2 N A F DB3 N A G DB4 N A E xit Enter the item letter to change any ID SYSTEM IN...

Page 47: ...type of problem Figure 21 Troubleshooting Screen Describing Circuit Problem I TIME 00 29 56 TROUBLESHOOTING DATE 08 15 99 CIRCUIT ID ___ ___ ___ ___ ___ ___ 1 1 1 1 1 ___ 2 ___ 2 ___ 2 ___ 2 ___ 2 __...

Page 48: ...r AutoUpdate is on or off Press to directly access the Loopback menu see Loopback Mode Screen on page 26 Legend symbols which appear in parentheses are also keyboard commands Type the symbol in parent...

Page 49: ...n lower than 4 dB Low margin is a result of high noise level and or low HDSL signal level Some causes of low margin Long loop External interference Excessive cross talk AUTOUPDATE OFF E xit A uto U pd...

Page 50: ...error has occurred An ERR symbol on the graph indicates a DS1 error has occurred The maximum value that can be displayed is 999 Some causes of HDSL errors Shorts interference noise Some causes of DS1...

Page 51: ...he SELF TEST message displays instead of the ALRM message One of the HDSL loops has lost synchronization Cannot be inhibited ALRM LLOS Local Loss of Signal Loss of the DSX 1 input signal Cannot be inh...

Page 52: ...em alarm press the SEL button and execute an Alarm Cut Off ACO An ACO turns the alarm off and replaces the ALRM message with an ACO message The second part of the ALRM message which defines the cause...

Page 53: ...k type from the Maintenance Terminal Main Menu when connected to the craft port of the HLU or HRU entering the loopback code into the test equipment connected to the HLU or HRU Generic Loopback Comman...

Page 54: ...pback towards the customer X X X CREM 1111110 6 in 7 Customer Remote Invokes HLU loopback towards the customer X X X SMJK LpUp PL 11000 2 in 5 SmartJack Loopup or NID payload PL code Invokes HRU loopb...

Page 55: ...k Telephone A5LB Teltrend Mod 1 Southern New England Telephone SNET Southwestern Bell Pacific Bell The A1LB loopback selection complies with that proposed for HDSL systems in the T1E1 4 92 recommendat...

Page 56: ...r 4 Type The display changes to MAN LPBK NLOC 5 Press MODE to advance to the next available loopback ND1 ND2 ND3 ND4 NRE CRE CD1 CD2 CD3 CD4 CLO 6 Press SEL to activate the selected loopback The previ...

Page 57: ...ualizers should be set to the distance from the DSX 1 to the shelf The transmit and receive T1 DSX 1 ports have splitting access jacks and miniature 210 series monitoring jacks as shown in Figure 1 on...

Page 58: ...LU 231 List 8A 5 Repeat Step 2 If the test passes the problem is in the downstream direction If it fails the problem is in the upstream direction Figure 28 Loopback Configurations Pressing the Loopbac...

Page 59: ...rrors detected by the test set varies from 229 to 231 depending on whether or not the test set counts frame errors as bit errors and on the number of frame bits contained in the block of 231 error bit...

Page 60: ...ler 4 was sent 20 errors if ILR 2 HRU was sent d normal looped data This error pattern repeats every 20 seconds as long as the IOR loopback pattern is being sent This also applies to ILR Time out Over...

Page 61: ...down disarmed and returned to normal operation send the disarm inband code 11100 or the ESF DL code FF24 The Armed mode has an automatic time out of 120 minutes but this timer is reset to 120 for any...

Page 62: ...Binary Code a Hexadecimal Equivalent a 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 The entire arm...

Page 63: ...0 DSX 1 Pulse Output 6 V pk pk pre equalized for 0 655 feet of ABAM cable DSX 1 Input Level 1 5 to 7 5 dBDSX DS1 Line Rate 1 544 Mbps 200 bps DS1 Line Format AMI B8ZS or ZBTSI DS1 Frame Format ESF SF...

Page 64: ...ain Table 17 describes line powered circuits on 9 kft 26 AWG loops without a doubler Table 16 HDSL Loss Over Cables Cable Gauge Loop Loss a dB per kft a At 196 kHz 68 F 20 C Loop Resistance per kft 26...

Page 65: ...3 1 6 3 6 9 494 543 HRU 411 OFF 20 22 0 6 2 6 8 471 518 Table 19 Power Parameters Single Doubler HDU 439 or HDU 437 Lists 1 and 1B HRU Model No HRU CPE Power 42 5 Vdc Power Consumption Watts Heat Diss...

Page 66: ...1 2 3 4 OFF 30 3 33 3 8 0 8 8 713 784 HRU 412 List 6 7 8 OFF 28 1 30 9 7 7 8 5 660 726 HRU 402 N A OFF 24 8 27 3 7 2 7 9 584 642 HRU 411 OFF 27 7 30 5 7 5 8 3 652 717 Table 23 Power Parameters Two Do...

Page 67: ...EV or other enclosures are determined by applying its power parameters to the manufacturer s requirements for each specific housing The 42 5 Vdc Power Consumption is the maximum total power that the H...

Page 68: ...rol Bus on pin 46 of the card edge connector This allows the various PairGain Management System protocols to manage the HLU through the HMU 319 HiGain Management Unit Whenever the HLU 231 is under man...

Page 69: ...21 Figure 29 on page 58 comprise the HLU 231 List 8A system alarm output These alarm contacts close for any system alarms condition See View Troubleshooting Screen on page 37 for further information...

Page 70: ...1 is shown in Figure 31 The HLU 231 receives a 1 544 Mbps DSX 1 data stream from the DSX 1 digital cross connect interface The HLU 231 contains a DS1 frame synchronizer controlled by an 8 bit micropro...

Page 71: ...high 112 Vdc applications When the circuit is active the system is compliant with Class A2 requirements of GR 1089 When the circuit is not active the system is compliant with Class A3 requirements of...

Page 72: ...plication enhancements of newer doubler models require that all circuit modules be of the same vintage in order to realize these enhancements Enhanced doubler applications preclude the mixing of newer...

Page 73: ...451 List 3 3B 4 4B HDU 437 439 HDU 404 407 409 Line Powered Local Powered Line Powered Local Powered Line Powered Local Powered HLU Model I CPE ON I CPE OFF I CPE ON I CPE OFF I CPE ON I CPE OFF I CP...

Page 74: ...he Customer Site portion of the PairGain Web page you need to provide a customer password If you do not have a password contact your PairGain sales representative RETURNS To return equipment to PairGa...

Page 75: ...on for returning the equipment please let us know so we can determine how best to help you 4 Pack the equipment in a shipping carton 5 Write PairGain s address and the Return Material Authorization RM...

Page 76: ...nit CDI Customer Disconnect Indicator HMS HiGain Management Shelf CI Customer Installation HMU HiGain Management Unit CLEI Common Language Equipment Identifier HRE HiGain Remote Enclosure CLOC Custome...

Page 77: ...ffice Repeater Bay SMJK SmartJack PCS Personal Communication Services SNR Signal to Noise Ratio PL Payload SPLB Special Loopback POTS Plain Old Telephone Service STS Span Terminating Shelf PPM Pulse P...

Page 78: ......

Page 79: ...t fails replace it with another unit and return the faulty unit to PairGain for repair Any modifications of the unit by anyone other than an authorized PairGain representative voids the warranty If a...

Page 80: ...Corporate Office 14402 Franklin Avenue Tustin CA 92780 7013 Tel 714 832 9922 Fax 714 832 9924 For Technical Assistance 800 638 0031...

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