ADTRAN DDM+ HTU-C M User Manual

JOBAID

DDM+

HTU-CM

CLEI:T1L3BWBA_ _

LED STATUS

STATUS ● GREEN Synchronization

✷ FLASHING ES, SES or BPV detected

● YELLOW Loopbacks active

✷ FLASHING In-band loopbacks armed

● RED Alarm on any HTU-C loops, HRE loops, DSX or DS1 interface

✷ FLASHING Signal Quality of 0 or No Sync on at least one loop

4 CHARACTER DISPLAY (FCD) OPERATION

UP = MODE CENTER = OFF DOWN = SELECT

FCD Modes

Mode Display Function

Status STAT HDSL loop margin, displays 1=xx or 2=xx, where xx=loop margin

0-2 marginal signal quality, 3-20 acceptable signal quality Display Off Blank Result after five minutes of no activity View VIEW View current parameters without changing Provisioning PROV Set configuration options Default DFLT Sets all factory defaults Loopback LPBK Select and execute HDSL circuit loopbacks

Status/Alarm Display (“STAT”)

Message Condition

HER1 CRC error detected on HDSL Loop 1 HER2 CRC error detected on HDSL Loop 2 LERR Frame bit error (SF Mode) or CRC error (ESF Mode) detected locally at DSX-1 of the HTU-C RERR Frame bit error (SF Mode) or CRC error (ESF Mode) detected locally at DS-1 of the HTU-C LBPV Bipolar Violation (BPV) detected locally at DSX-1 of the HTU-C RBPV BPV detected locally at DS-1 of the HTU-R LOS1 No synchronization of HTU-C and HTU-R on Loop 1 LOS2 No synchronization of HTU-C and HTU-R on Loop 2 LLOS DSX signal is absent from the network interface or is of a format which does not

match the provisioning of the HDSL circuit

RLOS DS1 signal is absent from the network interface or is of a format which does not

match the provisioning of the HDSL circuit

ARM The loopback arming sequence has been detected

HTU-R Options Display (“VIEW”)

Message Description Settings Default

TXLV DS1 Transmit Level 0 dB, -15 dB 0 dB PRM Performance Reporting Messages NPRM, SPRM, None None

Parameter Settings Display (“PROV”)

Message Description Settings Default

LBO DSX-1 Transmit Level 0, 133, 266, 399, 533 0 CODE Line Code AMI, B8ZS B8ZS FRMG DSX-1 Framing AUTO, ESF, SF, UNF, FFFC ESF NELB New England 1:6 loopback EN, DIS DIS NLBK NIU Loopback EN, DIS EN LBTO Loopback Timeout 0, 120 120 CLOS Customer Loss Response AIS, LPBK, CDI AIS LTCH Latching Loopback T1, FT1 T1 SPWR Span Power ON, OFF ON SALM Shelf Alarm EN, DIS EN

Loopback Options Display (“LPBK”)

Mode Select Loopback State Loopback Description

LPBK HTUC Net Network loopback at HTU-C

CST Customer loopback at HTU-C NONE No active loopback

HTUR BLB Bilateral loopback at HTU-R

NET Network loopback at HTU-R CST Customer loopback at HTU-R NONE No active loopback

HRE1 NET Network loopback at HRE1

CST Customer loopback at HRE1 NONE No active loopback

HRE2 NET Network loopback at HRE2

CST Customer loopback at HRE2 NONE No active loopback

WARRANTY

Carrier Network products manufactured by ADTRAN and supplied under Buyer’s order for use in the U.S. is ten (10) years. For a complete copy of ADTRAN’s U.S. Carrier Network Equipment Warranty: (877) 457-5007, Document 414.

COMPLIANCE CODES

This product is intended for installation in restricted access locations only and in equipment with a Type “B” or “E” installation code.

Input current at maximum load is 0.7 A at –48 VDC. Maximum output at over current condition is 165 mA at –190 VDC.

61246003L8-22B

0006

DDM+ HTU-CM

■ For a complete Installation and Maintenance Practice: (877) 457-5007, Document #455. Please have your fax number available. ■

CODE IN OUT

Installation Code (IC) A – Telecommunication Code (TC) – X

Power Code (PC) F C

C A U T I O N

HTU-C

1246003L8

MODE

SELECT

STATUS

R S 2 3 2

C A U T I O N

SUBJECT TO ELECTROSTATIC DAMAGE

OR DECREASE IN RELIABILITY.

HANDLING PRECAUTIONS REQUIRED.

MODE

SELECT

INSERTION LOSS MEASUREMENTS

10000 15.00

50000 25.50 100000 30.00 150000 32.75 196000 35.00 200000 35.25 250000 37.50 325000 42.00

NOTE: If your TIMs is unable to transmit 200 kHz tone, set

the TIMs to one of the frequencies shown above and compare the received signal to the maximum loss at that frequency.

Turn-up Guide

1. Set option switches according to specific circuit design

2. Install HTU-C and HTU-R

3. The status LED should be green, no alarm indications on the four-character display (FCD) and

synchronization has occurred

(a) HTU-C will display LLOS if not connected to network (no DSX present; LED will be solid red). (b) HTU-R will have red ALM LED if customer not connected. LP1, LP2, line coding (B8ZS or

AMI) and framing (ESF or SF) (if not UNFR) LEDs should be illuminated.

4. If Status LED is green: (a) Verify that the signal quality is the same on each loop. Ensure signal quality indicators do not

fluctuate.

(b) Verify that the loop loss is within design limits. If there is a difference of more than 1 dB

between the two loops, a problem exists with the cable pairs.

where they are occuring. See Troubleshooting Guide.

5. If everything checks out, proceed with BERT testing.

Troubleshooting Guide

The HTU-C status LED is flashing green and the FCD indicates "LERR," "HER1," "HER2" or "LBPV"

but no errors are indicated by the HTU-R

■ A BPV, Frame error (SF) or CRC error (ESF) has been detected at the DSX-1 interface. Possible net-

work or wiring problem between the HTU-C and the DSX. This is not an indication of problems on the HDSL loops.

The HTU-R DS1 LED is Flashing, but no Errors are Indicated by the HTU-C

■ A BPV, Frame Error (SF) or CRC Error (ESF) has been detected at the DS1 interface. This indicates a

Frequency Maximum

(kHz) Loss Data (dB)

wiring problem or a B8ZS/AMI mismatch between the HTU-R and the customer equipment. This is not an indication of problems on the HDSL loops.

The HTU-R has Power,but LP1 and LP2 LEDs are Dark.The Unit cannot Sync with the HTU-C

■ Simplex power for powering the HTU-R can be passed over cable pairs that contain load coils or

that are too long for HDSL synchronization. Using a TIMS, verify the circuit is within design limits.

■ The HTU-R will power up as long as there is at least one good conductor on each loop. To test,

remove the protector plug at the MDF and measure t-r resistance to the HTU-R on both loops. The HTU-R will place a 3 ohm short between t-r on both loops. An extremely high impedance indicates an open conductor. An extremely low reading on one loop may indicate a t-r short in the field. In the field, measure t-t and t-r voltage with the HTU-C installed and compare to the chart above. If these voltages are not present, open pairs or mis-wiring is indicated. As with other circuits, standard resistance measurements between each conductor and ground should also be used to test for a grounded conductor.

■ A high resistance open which degrades to the point that it causes the circuit to lose sync can

be “resealed” by reseating the HTU-C. Test the cable pairs before reseating the HTU-C.

Running Excessive Errors on the Loop

■ Measure t-r resistance as described above. If the pairs are unbalanced by more than 4 ohms, or

a measurement varies a great deal, this could indicate a high resistance open or an intermittent fault on the loop with the higher measurement. A TDR is typically required to locate this splice for repair.

■ Excessively long bridged taps can also cause errors. Check the records and/or use a TDR to verify

the location and length of bridged taps.

■ Using ADTRAN’s “Performance History” screen, it is often possible to see that many more errors

are being received on a particular loop or at a particular unit. The fault will typically be very close to the unit receiving the most errors.

No Power at the HTU-R

■ This could be caused by a loop with two open conductors. Measure t-r resistance from the MDF

to the HTU-R or use the voltage chart to see which pair is open.

HTU-C VMDF HRE 1 HRE2 HTU-R

AB CD EF

t-t Voltage t-t Voltage t-t Voltage t-t Voltage t-t Voltage t-t Voltage Circuit with 2 HREs (open at frame) 185 - 190 N/A N/A N/A N/A N/A Circuit with 0 or 1 HRE (open at frame) 145 - 150 N/A N/A N/A N/A N/A HTU-C / HTU-R 145 - 150 145 - 150 130 - 145 N/A N/A 125 - 130 HTU-C / HRE1 / HTU-R 130 - 135 110 - 135 110 - 135 N/A N/A 100 - 135 HTU-C / HRE 2 / HTU-R 185 - 190 160 - 185 160 - 185 140 - 185 140 - 185 130 - 185

NOTE: All measurements taken with HTU-C installed.With the HTU-C unseated or with protector removed at VMDF, t-r resistance will be cable resistance plus 3 ohms (for either HRE or HTU-R).

R S 2 3 2

STATUS

MODE

SELECT

HTU-C

1246003L8

HTU-R

1246026L4

M O N

B R G

LOC

ALM

DS1

LP2

LP1

LLB

(YEL)

RLB

(GRN)

B8ZS

(YEL)

AMI

(GRN)

ESF

(YEL)SF(GRN)

R S 2 3 2

REM

LBK

H D S

TURN-UP & TROUBLESHOOTING GUIDE

PRICING AND AVAILABILITY 800.827.0807

TECHNICAL SUPPORT 800.923.8726

RETURN FOR REPAIR 256.963.8722

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