Page 1
Model List Number Part Number CLEI Code HLU-231 150-1111-81 T1L2PY0AA ECHNOLOGIES NGINEERING ERVICES ECHNICAL RACTICE 150-231-181-01...
Page 2
Information furnished by PairGain Technologies is believed to be accurate and reliable. However, no responsibility is assumed by PairGain Technologies for its use; nor for any infringement of patents or other rights of third parties which may result from its use.
Page 3
Check the packing list to ensure complete and accurate shipment of each listed item. If the shipment is short or irregular, contact PairGain as described in the Warranty located inside the back cover. If you must store the equipment for a prolonged period, store the equipment in its original container.
Page 4
Inspecting the Shipment 150-231-181-01, Revision 01 September 7, 1999 HLU-231 List 8A...
150-231-181-01, Revision 01 Table of Contents ABLE OF ONTENTS Overview ____________________________________________________________________________ 1 Features ..............................1 Product Enhancements ......................1 Standard Features ........................1 Compatibility .............................2 Applications ............................2 HiGain Doubler Applications ....................2 Personal Communications System Applications ..............3 Front Panel __________________________________________________________________________ 4 Installation___________________________________________________________________________ 8 Verification ............................9 Verification without a Downstream Device ................9 Verification with a Downstream Device ................9 Provisioning Requirements ......................10...
Page 7
150-231-181-01, Revision 01 Table of Contents Initiating a Manual Loopback Session ..............46 Loopback Test Procedures .......................47 General Troubleshooting Tips ...................47 GNLB Test Procedures......................47 A1LB, A2LB, and A5LB Test Procedures................49 A3LB and A4LB Test Procedures..................52 Appendix A - Specifications____________________________________________________________ 53 HDSL Insertion Loss Guidelines .....................54 Power Consumption .........................54 Power Consumption without Doublers................54 Power Consumption with Doublers...................55...
Page 8
List of Figures 150-231-181-01, Revision 01 IST OF IGURES 1. HLU-231 List 8A Front Panel ........................4 2. Installing the HLU-231 List 8A into a Shelf ....................8 3. Maintenance Terminal Main Menu ......................14 4. System Spans ..............................15 5.
Page 9
150-231-181-01, Revision 01 List of Tables IST OF ABLES 1. Front-panel Description............................5 2. Front-panel Display Messages .........................6 3. Navigational Keys on the Maintenance Terminal ..................13 4. Maintenance Terminal Screens ........................14 5. Span Status Fields and Descriptions.......................17 6. HDSL System Alarms ............................18 7.
Page 10
List of Tables 150-231-181-01, Revision 01 September 7, 1999 HLU-231 List 8A...
Overview VERVIEW ® ® The PairGain HiGain Line Unit HLU-231 List 8A is the Central Office (CO) side of a repeaterless T1 transmission system. When used in conjunction with a HiGain Remote Unit (HRU), the system provides 1.544 Mbps transmission on two unconditioned copper pairs over the full Carrier Service Area (CSA) range. The CSA includes loops up to 12,000 feet of 24 AWG or 9,000 feet of 26 AWG wire, including bridged taps.
Overview 150-231-181-01, Revision 01 • Lightning and power cross protection on HDSL interfaces • Full duplex 2B1Q HDSL transmission on two pairs at 784 kbps • Margin threshold alarm OMPATIBILITY The HLU-231 List 8A is designed to be mounted in 220 mechanics shelves. For a list of compatible shelves, see “Appendix C - Compatibility”...
150-231-181-01, Revision 01 Overview Personal Communications System Applications The HLU-231 List 8A is required for Personal Communications System (PCS) applications that use the HRU-411. The HRU-411 has an onboard 130 Vdc, 8.5 W power supply that can power the 200 mW PCS remote radio ports.
Front Panel 150-231-181-01, Revision 01 RONT ANEL 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 to “Appendix A - Specifications”...
Page 15
150-231-181-01, Revision 01 Front Panel Table 1. Front-panel Description Front-panel Feature Function Front-panel display Displays four-character status, provisioning, and alarm system messages.The front-panel display illuminates when power is initially applied. To conserve power the display only remains on for 4 minutes. Using the MODE or SEL buttons reactivates the display and restarts the 4-minute timer. Refer to Table 2 on page 6 for a listing of the four-character messages.
Front Panel 150-231-181-01, Revision 01 Table 2 lists the front-panel display messages. The four-character displays reports the code of a pertinent alarm, loopback or diagnostic message, in some cases followed by a second four-character message that modifies the first message with a value or current configuration setting. Table 2.
Page 17
150-231-181-01, Revision 01 Front Panel Table 2. Front-panel Display Messages (Cont.) Message Full Name Description DS0 Blocked Channels Indicates status of DS0 blocked channels. NONE indicates no channels are blocked. BLK indicates some channels are blocked. FERR Framing Bit Error Framing bit error occurred at HLU T1 input.
Upon receipt of the equipment, visually inspect the contents for signs of damage. If the equipment has been damaged in transit, immediately report the extent of damage to the transportation company and to PairGain Technologies. When installing an HLU in a chassis, be sure to wear an antistatic wrist strap. Avoid touching components on the circuit board.
150-231-181-01, Revision 01 Installation ERIFICATION Once the HLU-231 is installed, verify that it is operating properly. To do this, you need to monitor the following: • Status LED • Status messages reported by the front-panel display (see Table 2 on page Verification without a Downstream Device If there is no downstream device installed: Verify that the HLU powers up.
Installation 150-231-181-01, Revision 01 ROVISIONING EQUIREMENTS Refer to “Provisioning” on page 11 for information about using the MODE and SEL buttons or the Maintenance Terminal screens to configure the HLU. While the MODE and SEL buttons can be used to manually accomplish some provisioning tasks, such as setting system options, the Maintenance Terminal screens (available when you connect a PC to the craft port) can handle all provisioning tasks.
150-231-181-01, Revision 01 Provisioning ROVISIONING This is a reference section for HLU provisioning. There are two methods for provisioning the HLU-231 List 8A: • Use the MODE and SEL buttons on the front panel of the HLU to: – set system options –...
Provisioning 150-231-181-01, Revision 01 Resetting to Factory Default Values All user options (Table 8 on page 21) can be set to the factory default values using the MODE and SEL buttons. To set the user options to their default values: Press the SEL button for 6 seconds until the following message appears: DFLT NO Press the SEL button while the DFLT NO message is displayed.
150-231-181-01, Revision 01 Provisioning SING A AINTENANCE ERMINAL Connecting to a Maintenance Terminal The craft port on the front panel allows you to connect the HLU-231 to a maintenance terminal (ASCII terminal or PC running a terminal emulation program). Once connected to a maintenance terminal, you can access the maintenance, provisioning, and performance screens.
Provisioning 150-231-181-01, Revision 01 Maintenance Terminal Main Menu Figure 3 shows the Maintenance Terminal Main Menu from which you can access system administration screens. The function of each screen selection is listed in Table 4. To access a screen, type the letter shown next to the menu item.
150-231-181-01, Revision 01 Provisioning Selecting a Maintenance Terminal Function To perform a function within the Maintenance Terminal screens, you can: • Press the key indicated to the left of the selection. • Press the letter in parenthesis for the parameter to be changed. System Spans As shown in Figure...
150-231-181-01, Revision 01 Provisioning Table 5 lists the Span Status fields and descriptions. Table 6 Table 7 on page 18 describe alarm and loopback messages displayed on the Span Status screens. Table 5. Span Status Fields and Descriptions Span Status Field Description Time Time of day when Span Status was checked.
Provisioning 150-231-181-01, Revision 01 Table 6. HDSL System Alarms Message Name Description Bit Error Rate The Total System Error Count (TSEC) has exceeded the user-selected threshold. LOSW Loss of Sync Word One of the HDSL loops has lost synchronization. LLOS Local Loss of Signal No signal from HLU-231 List 8A local T1 input.
150-231-181-01, Revision 01 Provisioning Set Clock Screen Press at the Maintenance Terminal Main Menu to open the Set Clock screen (Figure SET CLOCK TIME: 00:14:33 DATE: 08/05/99 CIRCUIT ID#: Format: HH:MM MM/DD/YY NEW TIME: NEW DATE: (U)PDATE REMOTE? Figure 7. Set Clock Screen All time information is lost when power is removed.
Provisioning 150-231-181-01, Revision 01 System Settings Screen The options set from the System Settings screen are the same as the options set through the HLU-231 Mode and SEL buttons on the front panel. The exceptions are Margin Alarm Threshold and DS0 Blocking, which can only be set at this screen.
150-231-181-01, Revision 01 Provisioning Table 8 describes the System Settings options and lists the corresponding front-panel display codes. Factory default parameters appear in boldface type. Table 8. HLU-231 List 8A System Settings Front-panel System Settings Display Parameter Description Screen Options Code Equalization Disables the HLU internal equalizer, allowing connection of external equalizer...
Page 32
Provisioning 150-231-181-01, Revision 01 Table 8. HLU-231 List 8A System Settings (Cont.) Front-panel System Settings Display Parameter Description Screen Options Code Alarm Opens the system alarm relay contacts if closed, and disables activation of the system alarm relay when a system alarm condition occurs. Enables activation of the system alarm relay when a system alarm condition occurs.
150-231-181-01, Revision 01 Provisioning Table 8. HLU-231 List 8A System Settings (Cont.) Front-panel System Settings Display Parameter Description Screen Options Code Alarm Pattern ALMP Enables HiGain to output an AIS payload at its T1 ports for LOSW, T1 LOS and Margin alarms.
Provisioning 150-231-181-01, Revision 01 BER Option The BER option also uses this (BPV/CRC) TEC to generate an Alarm if enabled. The HLU combines the 1-second TEC counts in both directions for the last 60 seconds. It uses this 1-minute Total System Error Count (TSEC) to generate an alarm if it exceeds the selected BER threshold of (1E-6 or 1E-7) as follows: •...
150-231-181-01, Revision 01 Provisioning Margin Alarm Threshold Option To set the Margin Alarm Threshold: Select from the System Settings Main Menu screen. Enter the desired minimum acceptable alarm threshold from the 0 to 15 dB range. This causes a system alarm to occur if either the margin on HDSL Loop 1 (MAL1) or Loop 2 (MAL2) drops below the selected threshold value.
Provisioning 150-231-181-01, Revision 01 If the HLU-231 is used with the HRU-411 to power PCS sites, the PWRF option should be set to AUTO. This causes the HLU to automatically detect the need to switch to the HIGH power feed mode when it receives a request from the HRU to do so.
150-231-181-01, Revision 01 Provisioning Loopback Menu without Doubler LOOPBACK MENU TIME: 00:15:34 DATE: 08/05/99 CIRCUIT ID#: A. DISABLE LOOPBACKS B. NETWORK LOOP HLU (NLOC) C. NETWORK LOOP HRU (NREM) G. CUSTOMER LOOP HLU (CREM) H. CUSTOMER LOOP HRU (CLOC) (E)xit Figure 9.
Provisioning 150-231-181-01, Revision 01 Initiating a Loopback To send one of the available loopbacks, press the appropriate letter in the Loopback Menu. The following prompt appears: )? Type to continue with the loopback selection. The PERFORM SELECTED LOOPBACK ( following message appears: PLEASE WAIT....
150-231-181-01, Revision 01 Provisioning View Performance Data Screen The Performance Data screen shows the Errored (ES) and Unavailable Seconds (UAS) for both HDSL loops and each T1 input at 15-minute intervals over a 4-hour time interval. (The ES and UAS data is separated by a slash mark.) Earlier and later data, in 4-hour time periods on different span screens, can be accessed by pressing (Previous) or (Next) respectively.
Provisioning 150-231-181-01, Revision 01 Performance Data Screen without Doubler Figure 12 shows a single non-doubler span. This screen shows the Errored and Unavailable Seconds for the HDSL span between the HLU-231 and the HRU. Invalid report entries are indicated by dashes. Date: 08/05/99 PERFORMANCE DATA CIRCUIT ID#:...
150-231-181-01, Revision 01 Provisioning View Performance History Screen The Performance History screen shows the daily occurrences of ES and UAS over a 31-day period in 24-hour increments. Errored Seconds and Unavailable Seconds for both HDSL loops and each of the two DS1 inputs are listed for the current and previous period.
Provisioning 150-231-181-01, Revision 01 Performance History Screen for Doubler Applications The Performance History screen displays information by span when doublers are present. With multiple doublers (up to four), there can be as many as five span screens. Invalid report entries are indicated by dashes. Time: 00:26:29 SPAN 5 PERFORMANCE HISTORY - 31 DAY CIRCUIT ID#:...
150-231-181-01, Revision 01 Provisioning View Alarm History Screen Press at the Maintenance Terminal Main Menu to open the Alarm History screen. This screen allows you to view alarms that are currently active. In the Alarm History screen (Figure 16 Figure 17 on page 34) the: •...
150-231-181-01, Revision 01 Provisioning View System Inventory Screen The System Inventory screen (Figure 18 on page 36) lists the six possible units that can comprise one HiGain circuit: one HLU, one HRU and up to four doublers. The information in the System Inventory Screen is presented as follows: •...
Provisioning 150-231-181-01, Revision 01 System Inventory Screen without Doubler SYSTEM INVENTORY TIME: 04:17:37 DATE: 08/05/99 A. CIRCUIT ID: UNIT PRODUCT SERIAL NUMBER UNIT ID HLU-231 L8A V7.1 ..000004 NOT REQUIRED B. HRU HRU-402 V1.5 3499000400 C. DB1 D. DB2 F. DB3 G.
150-231-181-01, Revision 01 Provisioning View Troubleshooting Screen The Troubleshooting screen graphically analyzes the circuit and identifies any problem areas. Press at the Maintenance Terminal Main Menu to access the Troubleshooting screen. The Troubleshooting screen (Figure 20) appears showing the HLU, the HRU and any doublers that are in the circuit (up to four). HDSL Line 1 TIME: 00:29:56 TROUBLESHOOTING...
Provisioning 150-231-181-01, Revision 01 To display the circuit Help diagram (Figure 22), press . The symbol legend used to describe all circuit events and the corresponding troubleshooting tips are located beneath the Help diagram. A troubleshooting symbol on the diagram identifies the location of a problem. Legend symbols which appear in parentheses are also keyboard commands.
150-231-181-01, Revision 01 Troubleshooting ROUBLESHOOTING This section provides information about system alarms and loopback testing. In addition to these troubleshooting aids, the Maintenance Terminal provisioning interface includes troubleshooting screens that provide a basic graphical analysis of system problems (see “View Troubleshooting Screen” on page 37).
Troubleshooting 150-231-181-01, Revision 01 Alarm Option for DLC Feed To improve HiGain compatibility with the switch-to-protect features used in DLC feeder applications, the HLU-231 has an Alarm Pattern Option (ALMP) that allows you to select either an AIS or LOS T1 output payload for the following alarms: •...
150-231-181-01, Revision 01 Troubleshooting OOPBACK PERATION HiGain has a family of loopback options for analyzing circuit functionality. The loopback signal is transmitted and returned to the sending device for comparison. This allows you to verify the integrity of the HDSL channels to the HLU, the HLU DSX-1 interface and the DS1 channels to the customer.
Page 54
Troubleshooting 150-231-181-01, Revision 01 Table 13. Summary of HiGain Loopback Codes Method of Transmission Loopback Code Description Test Set Craft Port MODE/SEL NLOC 1111000 Network Local. Invokes HLU loopback toward the network. 4-in-7 NDU1 110000 Network Doubler 1. Invokes HDU1 loopback toward the network.
150-231-181-01, Revision 01 Troubleshooting Special Loopback Commands In addition to the GNLB loopback command mode, a HiGain system can be configured for one of five special loopback command modes. These are selected from the maintenance terminal System Settings screen (see Table 8 on page 21) or by using the MODE and SEL buttons (see...
Troubleshooting 150-231-181-01, Revision 01 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.
150-231-181-01, Revision 01 Troubleshooting Once a loopback is selected and activated, the loopback stays active until it times out (based on the LBTO setting). When a loopback times out, the display then returns to the normal display mode. You can terminate loopbacks manually and exit the MAN LPBK mode by simultaneously pressing the MODE and SEL buttons for 3 or more seconds.
Page 58
Troubleshooting 150-231-181-01, Revision 01 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 Loopback button on a remote unit will deactivate the SmartJack loopback. September 7, 1999 HLU-231 List 8A...
150-231-181-01, Revision 01 Troubleshooting A1LB, A2LB, and A5LB Test Procedures Using the codes listed in Table 14, a network tester can activate NLOC or NREM loopbacks (or SMJK, if enabled). A tester at the customer premises can activate CLOC or CREM loopbacks. All loopbacks shown in Table 14 can also be initiated from the HLU-231 front-panel MODE and SEL buttons (see “Setting Options...
Page 60
To avoid this uncertainty, PairGain recommends sending unframed IR commands. The HLU is now in logic loopback if the IOR NLOC loopback command was sent. The Time-out Override command or a Loopdown command can override the selection made for the loopback time-out (see “Setting...
Page 61
150-231-181-01, Revision 01 Troubleshooting Once the test is complete, do one of the following: • If the system is to loopdown but remain Armed, send the IR LPDN code (universal loopdown). • If all the equipment is to be looped down, disarmed and returned to normal operation, send the disarm inband code 11100 or the ESF-DL code (FF24).
Troubleshooting 150-231-181-01, Revision 01 A3LB and A4LB Test Procedures The HLU-231 can be looped back by sending the Addressable Office Repeater (AOR) LPBK activation code 1111-1111-0001-1110 (FF1E) for at least 5 seconds. This causes the HLU-231 to enter the NLOC state. The Loopback Time-out setting (see “Setting the Loopback Time-out Option”...
150-231-181-01, Revision 01 Appendix A - Specifications A - S PPENDIX PECIFICATIONS This appendix provides general specifications, pinout diagrams for the craft port and card-edge connector, HDSL insertion loss guidelines, and power consumption and dissipation tables. HDSL Line Code 784 kbps 2B1Q HDSL Output +13.5 dBm ±0.5 dB at 135 HDSL Line Impedance...
1.54 (a) At 196 kHz, 68°F (20°C) A Windows-based program, Cable Calculator, may be downloaded from the Customer site portion of the PairGain web site at www.pairgain.com. If you don’t have a customer password, contact your sales representative. OWER ONSUMPTION Power consumption and heat dissipation depends upon the type of remote and doubler units in the system and the CPE power setting.
150-231-181-01, Revision 01 Appendix A - Specifications Power Consumption with Doublers Table 18 through Table 24 list the power consumed and dissipated by the HLU-231 when it is used with any of the four basic doubler types in the HiGain family. The maximum current drawn by the CO supply is also listed. Table 18 through Table 20...
Appendix A - Specifications 150-231-181-01, Revision 01 Table 21 through Table 23 show power parameters for two doubler, line-powered circuits on 9 kft, 26 AWG loops. Table 21. Power Parameters—Two Doublers (HDU-451 List 3, 4, 3B or 4B) HRU CPE 42.5 Vdc Power HRU Model No.
150-231-181-01, Revision 01 Appendix A - Specifications AXIMUM OWER ISSIPATION The Maximum Power Dissipation measures the power that is converted into heat that builds up within the unit. It contributes to the total heat generated in the space around the unit. It is used to determine the maximum number of fully loaded shelves per bay that does not exceed the maximum allowable power dissipation density in watts per square foot to comply with GR-63.
The HLU-231 List 8A provides a Network Management Control 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 management, the MNGD message displays periodically on the HLU front-panel display.
150-231-181-01, Revision 01 Appendix A - Specifications System Alarm Relay Output The normally open alarm contacts available across pins 20 and 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”...
UNCTIONAL PERATION PairGain HDSL technology provides full-duplex services at standard T1 rates over copper wires between an HLU and an HRU, which comprise one HiGain system. HiGain systems use PairGain 2-Binary 1-Quartenary (2B1Q) HDSL transceiver systems to establish two, full-duplex, 784 kbps data channels between the HLU-231 and a remotely located HDU or HRU.
150-231-181-01, Revision 01 Appendix B - Functional Operation ROUND AULT ETECT The HLU-231 has a Ground Fault Detect (GFD) circuit which detects a ground or a resistive path to ground on any wire of any loop of any span with a non-zero voltage. For low (-140 Vdc) applications, such a circuit is active during start-up by applying the bipolar voltage to the loops.
T1 R EPEATER HELVES AND ELATED QUIPMENT The HLU-231 List 8A is compatible with the following T1 repeater shelves and associated equipment: • PairGain HCS-417 (23”) • PairGain HCS-418 (19”) • PairGain HCS-402 (2-slot)) • AT&T 220 Office Repeater Bay (ORB) •...
Page 73
150-231-181-01, Revision 01 Appendix C - Compatibility Table 25. HiGain Doubler Deployment Matrix Maximum Number of Doublers Per Circuit HDU-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 HLU-231...
PairGain Customer Service Group provides expert pre-sales and post-sales support and training for all its products. ECHNICAL UPPORT Technical assistance is available 24 hours a day, 7 days a week by contacting PairGain Customer Service Group at: 800.638.0031 or 714.832.9922 Telephone: The 800 telephone support line is toll-free in the U.S.
Page 75
Pack the equipment in a shipping carton. Write PairGain’s address and the Return Material Authorization (RMA) Number you received from the RMA Department clearly on the outside of the carton and return to: PairGain Technologies, Inc.
Appendix E - Glossary 150-231-181-01, Revision 01 E - G PPENDIX LOSSARY 2B1Q 2 Binary,1 Quaternary DSX-1 DS1 Cross-connect Frame Alarm Cut Off Equipment Catalog Item Alarm Indication Signal indicated by Enabled transmission of an all ones pattern ALMP Alarm Pattern ENFT Enable Fractional T1 Alternate Mark Inversion...
Page 77
150-231-181-01, Revision 01 Appendix E - Glossary Network Management and Administration Return Material Authorization NREM Network Remote Loopback SAIS SmartJack AIS NVRAM Non-Volatile Random Access Memory Super Frame Office Repeater Bay SMJK SmartJack Personal Communication Services Signal-to-Noise Ratio Payload SPLB Special Loopback POTS Plain Old Telephone Service...
Do not try to repair the unit. If it 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.
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...
Need help?
Do you have a question about the T1L2PY0AA and is the answer not in the manual?
Questions and answers