HDSL4 TROUBLESHOOTING GUIDE

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ADTRAN HDSL4 equipment is designed with troubleshooting-at-a-glance features. The following information provides suggestions for troubleshooting as a result of LED indications which are indicative of loop trouble.

NOTE: Pressing “ESC” while on any screen will go back to the previous screen.

LOOPBACK AND CONTROL CODES

INDICATIONS AND POSSIBLE CAUSES

DSL LED Red

Connect a terminal or PC to the RS-232 (DB-9) craft interface on the front panel. The terminal must be VT100 or compatible and set for 1.2 to 19.2 kbps, 8 data bits, no parity, 1 stop bit, no flow control. Select “3” from the ADTRAN HDSL4 Main Menu screen and “1” from the Span Status Screen. Verify the following conditions on the HDSL4 and T1 Detailed Status Screen:

Margin ≥ 3 dB

Attenuation ≤ 35 dB (1st segment) Attenuation ≤ 31 dB (2nd segment)

No ES, SES, or UAS (Performance History Screen, Main Menu Selection 5)

If the above conditions do exist, the circuit should provide quality service; however, if any of the above conditions do not exist, a cable problem or excessive loss situation is probable, and more detailed cable testing should be done to verify all HDSL4 loop specifications are met. These conditions may also reflect intermittent cable faults or excessive noise impairments. If intermittent faults or noise impairments are suspected, review the Performance History Screen.

HDSL4 DEPLOYMENT GUIDELINES

NOTE: The insertion loss reading shown on the Detailed Status

The guidelines provided below apply to the segments of an

Screen is an approximation that is valid for some loops.

HDSL4 circuit, as follows:

Exercise caution when using this value.

 

1st segment = between the H4TU-C and H4R

 

2nd segment = between two H4Rs or single H4R and H4TU-R

 

3rd segment = between the second H4R and the H4TU-R

 

These deployment guidelines provide the basics for HDSL4 circuit provisioning. If these parameters are met, then the circuit will provide quality service. If not, a cable problem or excessive loss situation is probable. In this case, a more detailed cable analysis is required to ensure that all HDSL4 loop specifications are met. These conditions may also be the result of intermittent cable faults or intermittent noise impairments. If intermittent problems are suspected, utilize the Performance History screen to assist in troubleshooting.

1.

All loops are nonloaded only

 

 

Range Limits: 26 Gauge / 70ºF / PIC

 

2.

Any single bridged tap is limited to 2 kft.

 

 

 

Recommended Maximum

 

 

 

 

(DSL Assistant Green Zone)

 

3.

Total bridged tap length is limited to 2.5 kft.

 

 

 

 

 

 

1st segment

 

10.8 kft.

 

4.

Bridge tap within 1000 feet of units may affect performance of the

 

 

2nd/3rd segment

 

10.55 kft.

 

 

circuit

 

 

 

 

 

 

 

 

 

 

 

5.

Margin ≥ 6 dB (Detailed Status Screen)

 

 

Range Limits: 24 Gauge / 70ºF / PIC

 

6.

No ES, SES, or UAS (Performance History Screen)

 

 

 

Recommended Maximum

 

7.

Foreign Voltage DC (t-r, t-g, r-g) < 3 VDC

 

 

 

(DSL Assistant Green Zone)

 

8.

Insulation Resistance (t-r, r-g, t-g) > 3.5 MΩ

 

 

1st segment

 

15.25 kft.

 

9.

Impulse Noise ≤ –40 dBmF (measured with an F filter)

2nd/3rd segment

 

15.05 kft.

 

10. Wideband Noise ≤ –54 dBmF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Attenuation Limits

 

11. Longitudinal Noise (Power Influence) < 80 dBrnC

OK

 

 

 

 

 

Recommended Maximum

 

 

80–90 dBrnc

Marginal

 

 

 

 

 

 

(DSL Assistant Green Zone)

 

 

> 90 dBrnc

Unacceptable

 

 

 

 

 

 

Upstream

Downstream

 

 

 

 

 

 

 

 

 

 

 

1st segment

31 dB

33 dB

 

 

 

 

 

2nd/3rd segment

30 dB

30 dB

 

 

 

 

 

 

 

 

 

Pattern

Description

Requires Arming?

1in3

Loop down all units and disarm.

No

2in5

Arming Pattern, H4TU-R will loop up if Smartjack LB is enabled.

No

3in5

Disarm and loop down all units. Restores LB TMO after D5D6.

No

1in6

Network Arming Pattern. If Smartjack LB is enabled, HTU-R will loop toward network.

No

2in6

H4R LB to Network.

 

No

3in6

H4R LB to Network.

 

No

4in6

H4R LB to Customer.

 

No

5in6

H4R LB to Customer.

 

No

3in7

H4TU-R LB to Network.

 

No

4in7

H4TU-C LB to Network.

 

No

5in7

H4TU-R LB to Customer.

 

No

6in7

H4TU-C LB to Customer.

 

No

3F1E

H4TU-C LB to Customer.

 

No

3F02

H4TU-R LB to Customer.

 

No

3F04

H4R LB to Customer.

 

No

3F06

H4R LB to Customer.

 

No

6767

Disable span powering while present.

Yes

9393

Loop down H4TU-C, Repeaters - all loopbacks. Loop down H4TU-R - Cust LB always.

 

 

Will only loop down H4TU-R Network LB if NIU is disabled. Does not disarm units if they

 

 

are armed.

 

No

C741

H4R #1 loop up pattern.

10 bit error injection.

Yes

C742

H4TU-R loop up pattern.

20 bit error injection.

Yes

C754

H4R #2 loop up pattern.

200 bit error injection.

Yes

D3D3

H4TU-C loop up pattern.

231 bit error injection.

Yes

D5D5

Query Loopback Pattern (error injection)

 

 

H4TU-C: 231 Errors, H4R #1: 10 Errors, H4R #2: 200 Errors, H4TU-R: 20 Errors

No

D5D6

Loopback Timeout Override: Disables LB timeout. Restores original LB timeout when unit

 

 

is disarmed.

 

Yes

FF48

FDL Arming Pattern (ESF only). Arms all units, H4TU-R will LB to Network if NIU Enabled

 

 

(if pattern sources at network).

No

FF24

FDL Disarm Pattern (ESF only). Loop down and disarm all units

No

FF1E

H4TU-C LB to Network. Will not loop up H4TU-C if H4TU-C already in LB to Customer.

No

FF02

H4TU-R LB to Network. Will not loop up H4TU-R if any unit already in LB to Customer.

No

FF04

H4R LB to Network.

 

No

FF06

H4R LB to Network.

 

No

WARRANTY

ADTRAN will replace or repair this product within the warranty period if it does not meet its published specifications or fails while in service. Warranty information can be found at www.adtran.com/warranty. U.S. and Canada customer Faxback: 877-457-5007, Document 414.

NOTE: In three segment circuits (two H4Rs), individual segment resistance values must be verified. Refer to the HDSL4 Deployment Guidelines section of the Installation and Maintenance Practice (P/N 61222404L1-5x) for those guidelines.

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ADTRAN 3192 H4TU-C manual Range Limits 26 Gauge / 70ºF / PIC, Recommended Maximum, Range Limits 24 Gauge / 70ºF / PIC