PairGain HiGain Line Unit HLU-388 Quick Installation Manual Download Page 5

L

OOPBACK

 T

ESTING

Initiate loopback testing from the HiGain maintenance menus or use the MODE and SEL 
buttons. The hexidecimal inband codes shown below can be sent by a test set.

GNLB Loopback Commands

Loopback

Inband Code

Description

NLOC

1111000

DSX-1 signal is looped back to the network at the HLU.

NDU1

110000

DSX-1 signal is looped back to the network at the HDU1.

NDU2

111000

DSX-1 signal is looped back to the network at the HDU2.

NDU3

1010001

DSX-1 signal is looped back to the network at the HDU3.

NDU4

1010010

DSX-1 signal is looped back to the network at the HDU4.

NREM

1110000

DSX-1 signal is looped back to the network at the HRU.

SMJK

11000

DSX-1 signal is looped back to the network at the HRU SmartJack 
module.

CLOC

1111100

Signal from customer is looped back to the customer at the HLU.

CDU1

111100

Signal from customer is looped back to the customer at the HDU1.

CDU2

111110

Signal from customer is looped back to the customer at the HDU2.

CDU3

1011001

Signal from customer is looped back to the customer at the HDU3.

CDU4

1011010

Signal from customer is looped back to the customer at the HDU4.

CREM

1111110

Signal from customer is looped back to the customer at the HRU.

Loopdown

11100

Deactivates any of the above loopbacks.

For more detailed information about the Maintenance Terminal 
screens, provisioning, and loopback mode testing, refer to the 
HLU-388 List 5A technical practice, document number 
150-388-151-xx. It can be downloaded from the Customer Site portion 
of the PairGain Web page at www.pairgain.com
. A password is 
required to access the Customer Site Web pages. If you do not have 
a password, contact your PairGain sales representative.

Front-Panel Alarm Messages

 (a)

(a)

Alarm (ALRM) displays prior to an alarm message.  Pressing the SEL button initiates an Alarm Cutoff (ACO) 
message.

Message

Description

LOSW

Indicates that one of the HDSL loops has lost sync. 

LLOS

Indicates that no signal is detected at the DSX-1 input to the HLU. 

RLOS

Indicates that no signal is detected at the DS-1 input to the HRU.

BER

A system Bit Error Rate alarm is in effect.

MAL1 or MAL2

The margin on HDSL Loop 1 or Loop 2 has dropped below the threshold set by the user.

NONE

No alarm present.

System Configuration Codes

Code

Description

VER xxxx

The release revision of the firmware (appears during the System Settings review mode).

LIST xxxx

The model number of the product (appears during the System Settings review mode).

FRM xxxx

Indicates the type of frame pattern being received from the DSX-1, where xxxx is SF, 
ESF, UNFR, or NONE).

CODE xxxx

The line code setting, where xxxx is Alternate Mark Inversion (AMI) or Bipolar with 
8-Zero Substitution (B8ZS).

PLEV xxxx

Indicates the HDSL line voltage in its LOW (-140 Vdc), HIGH (±112 Vdc), or DIS 
(disabled).

Front-Panel Diagnostic Messages

Message

Description (normal operating messages in bold)

1=xx or 2=yy

Indicates the power of the received HDSL signal on each loop relative to noise. Any value 
of 06 (dB) or greater is adequate for reliable system operation.

ACQ1 or ACQ2

The multiplexers of the HLU and the HRU or the first doubler are trying to establish 
synchronization over Loop 1 or Loop 2 of Span 1.

AnL1 or AnL2

The multiplexers of the two devices on Span n are trying to establish synchronization with 
each other on Loop 1 or Loop 2, where n is the number of the span.

BAD RT?

The HLU is not receiving any response from the HRU. 

DSO

NONE = no DSO channels blocked. BLK = some channels blocked.

FERR

Framing bit error occurred at HLU DSX-1 input.

H1ES or H2ES 

HDSL Loop 1 or Loop 2 CRC error.

nHDU

Indicates the number (n) of doublers in the circuit (if any are present).

INSL xxdB

The maximum Insertion Loss message (INSL) appears followed by xxdB, where xx is the 
maximum insertion in dB of all spans and loops.

LBPV

A local bipolar violation has been received at the DSX-1 input to the HLU-388 List 5A.

MNGD

The HLU is under control of the HMU-319 network management unit. 

PWR FEED GND

One of the HDSL loops has been grounded.

PWR FEED ON

Indicates that the HDSL loops are not grounded or shorted.

PWR FEED OFF 

HDSL span power has been turned off.

PWR FEED SHRT

Indicates a short between the two HDSL pairs or the inability of the HRU to communicate 
with the HLU.

SELF TEST

The HLU is in a self-test mode. This occurs every power on/off cycle.

SIG1 or SIG2

The transceivers of the HLU and HRU or first doubler are trying to establish contact with 
each other on Loop 1 or Loop 2 of Span 1.

SnL1 or SnL2

The transceivers of the two devices on Span n are trying to establish contact with each 
other on Loop 1 or Loop 2, where n is the number of the span.

TLOS

HRU is in a logic loopback state caused by a loss of its T1 input from the CI.

System Settings

Display Code

Description (default values in bold)

EQL

Sets the Equalizer (EQL) DSX-1 to: 0 (0 to 133 ft.), 133 (133 to 266 ft.), 266 (266 to 399 
ft.), 399 (399 to 533 ft.), 533 (533 to 655 ft.).

LPBK

Enables (ENA) or disables (DIS) all inband SMJK loopback commands.

SPLB

Configures the system for generic inband loopback commands (GNLB) or special 
loopback commands (A1LB, A2LB, A3LB, A4LB, A5LB).

PWRF

DIS = disables HDSL powering. 
LOW = HDSL line voltage at -140 Vdc maximum.
AUTO = automatically switches between -140 Vdc for non-doubler applications and 
±112 Vdc for doubler applications. 
HIGH = ±112 Vdc for all applications.

ZBTS

ON = ESF frame is operating in its Zero-Byte Time Slot Interchange (ZBTSI) mode.
OFF = ESF frame is operating in its normal non-ZBTSI mode.

BERT

NONE = prevents generation of a system alarm due to excessive BER.
1E-6 or 1E-7 = alarm activates when BER threshold exceeds 10

-6

 or 10

- 7

, respectively.

LBTO

Loopback timeout = NONE, 20, 60, 120 minutes.

DS1

Line code = , AUTO, B8ZS, or AMI.

FRMG

Framing = AUTO or UNFR (unframed).

HAIS

Transmits the AIS signal at the HLU and HRU output ports if one (1LP) or both (2LP) HDSL 
loops are not in sync.

SAIS

Enables (ENA) or disables (DIS) NREM/SMJK loopback mode.

DSO

DSO blocking on (BLK) or off (NONE); can only be set through the Maintenance Terminal.

MARG

0 to 15 dB; default is 4dB; can only be set through the Maintenance Terminal.

RDA

Enables (ENA) or disables (DIS) remote DS1 LOS at HRU input.

ALMP

Enables line to output an (AIS) payload or an (LOS) condition.

RTPV

Enables (ENA) or disables (DIS) remote provisioning.

BPVT

Enables (ENA) or disables (DIS) bipolar violation transparency (BVP).

CONF

YES = confirms that all operating modes are to be updated to their current selections.
NO = prevents the most recently selected operating mode selection from being updated.

Summary of Contents for HiGain Line Unit HLU-388

Page 1: ...eaterless 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 American Wire Gauge AWG or 9 000 feet of 26 AWG wire including bridged taps This line unit can be used in applications with or without HiGain ...

Page 2: ...peaterless 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 American Wire Gauge AWG or 9 000 feet of 26 AWG wire including bridged taps This line unit can be used in applications with or without HiGain...

Page 3: ...peaterless 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 American Wire Gauge AWG or 9 000 feet of 26 AWG wire including bridged taps This line unit can be used in applications with or without HiGain...

Page 4: ...over Loop 1 or Loop 2 of Span 1 AnL1 or AnL2 The multiplexers of the two devices on Span n are trying to establish synchronization with each other on Loop 1 or Loop 2 where n is the number of the span BAD RT The HLU is not receiving any response from the HRU DSO NONE no DSO channels blocked BLK some channels blocked FERR Framing bit error occurred at HLU DSX 1 input H1ES or H2ES HDSL Loop 1 or Loo...

Page 5: ...ver Loop 1 or Loop 2 of Span 1 AnL1 or AnL2 The multiplexers of the two devices on Span n are trying to establish synchronization with each other on Loop 1 or Loop 2 where n is the number of the span BAD RT The HLU is not receiving any response from the HRU DSO NONE no DSO channels blocked BLK some channels blocked FERR Framing bit error occurred at HLU DSX 1 input H1ES or H2ES HDSL Loop 1 or Loop...

Page 6: ...ver Loop 1 or Loop 2 of Span 1 AnL1 or AnL2 The multiplexers of the two devices on Span n are trying to establish synchronization with each other on Loop 1 or Loop 2 where n is the number of the span BAD RT The HLU is not receiving any response from the HRU DSO NONE no DSO channels blocked BLK some channels blocked FERR Framing bit error occurred at HLU DSX 1 input H1ES or H2ES HDSL Loop 1 or Loop...

Page 7: ...eaterless 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 American Wire Gauge AWG or 9 000 feet of 26 AWG wire including bridged taps This line unit can be used in applications with or without HiGain ...

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