Any brand names and product names included in this manual are trademarks, registered trademarks, or trade names of their respective holders.
To the Holder of the Manual
The contents of this publication are current as of the date of publication. ADTRAN reserves the
right to change the contents without prior notice.
In no event will ADTRAN be liable for any special, incidental, or consequential damages or for
commercial losses even if ADTRAN has been advised thereof as a result of issue of this publication.
DOctober 2004Updated to add Bad Splice Detect and Fast Retrain feature
Conventions
The following typographical conventions are used in this document:
This font indicates a cross-reference link. First-time references to tables and figures are shown in
this font.
This font indicates screen menus, fields, and parameters.
THISFONT indicates keyboard keys (ENTER, ESC, ALT). Keys that are to be pressed simultaneously
are shown with a plus sign (
same time).
Thisfont indicates references to other documentation and is also used for emphasis.
descriptions
ALT+X indicates that the ALT key and X key should be pressed at the
This font indicates on-screen messages and prompts.
This font indicates text to be typed exactly as shown.
This font indicates silkscreen labels or other system label items.
This font is used for strong emphasis
NOTE
Notes inform the user of additional but essential information or features.
CAUTION
Cautions inform the user of potential damage, malfunction, or disruption to equipment, software, or environment.
WA R NI N G
Warnings inform the user of potential bodily pain, injury, or death.
61223445L1-5D iii
Training
239 H4R Installation and Maintenance Practice
ADTRAN offers training courses on our products. These courses include overviews on product
features and functions while covering applications of ADTRAN’s product lines. ADTRAN
provides a variety of training options, including customized training and course taught at our facilities or at customer sites. For more information about training, please contact us.
Tables239 H4R Installation and Maintenance Practice
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vi 61223445L1-5D
239 T1 HDSL4 Repeater (H4R)
1.GENERAL
This practice is an installation and maintenance guide for the ADTRAN® 239 T1 HDSL4 Repeater (H4R) (239
H4R). Figure 1 illustrates the 239 H4R (P/N 1223445L1) front panel.
239 H4R
1223445L1
LP1
NET
LP2
LP1
CUST
LP2
LL RL
/
(Y) (G)
Figure 1. HDSL4 239 T1 HDSL4 Repeater (H4R)
2.DESCRIPTION
HDSL4 provides extended range T1 (DS1) transport on the telecommunications network. HDSL4 features spectral
compatibility with ADSL and other transport technologies.
This 239 H4R performs signal regeneration to extend the range of the HDSL4 circuit.
The H4TU-C (Central Office Transceiver) unit receives DSX-1 input signals from the network through the chassis,
transports them across the HDSL4 circuit, and terminates them through an H4TU-R remote unit which provides a
traditional DS1 to customer equipment. The H4TU-C provides testing, provisioning, and performance monitoring
capabilities that address circuit status.
The H4TU-C works in conjunction with the ADTRAN H4TU-R (Remote) and up to three H4Rs (Repeaters) to
provide a DS1 service on the local loop.
61223445L1-5D 1
Description239 H4R Installation and Maintenance Practice
Features
The basic features of the HDSL4 239 T1 HDSL4 Repeater (H4R), include the following:
• TC PAM line coding
• Lightning protection
• In-band loopback control
• Standard 239 form factor repeater apparatus case design
• Remote provisioning and pass-through performance monitoring
• Bad Splice Detection
• Fast Retrain
Bad Splice Detection Feature
This 239 H4R supports the Runtime TScan 2.0
sive algorithm for detection of anomalies (bad splices) in the copper pair.
Data transmission transceivers (especially echo-cancelled technologies) are subject to performance degradations
and errors in the presence of bad splices. A splice may be benign for a period of time, allowing a circuit to behave
appropriately for portions of the day. However, over time the splice will oxidize and incur small, rapid changes in
impedance. This inconsistency in behavior makes the problem difficult to locate. Additionally, an impedance
change that is large enough to cause the transceiver trouble may still be small enough to be undetected by test
equipment utilized on the copper pairs. Therefore a non-intrusive method of identifying these bad splices has been
developed to aid the customer in troubleshooting their distribution plant.
TM
bad splice detection feature, an ADTRAN proprietary non-intru-
NOTE
The Splice Detection Feature is included with this product as an aid to troubleshooting. Due to inconsistency in environmental conditions and their effect on
telecommunications plant, ADTRAN cannot guarantee the accuracy of the
measurements. Comparison to existing engineering drawings should provide exact
locations of suspect splices indicated by ADTRAN algorithms.
Splices that are varying in impedance will cause the HDSL data pump to see a reduced and/or fluctuating signal
quality (margin). The HDSL data pump will attempt to track these changes. When the changes become too severe,
errors or loss of synchronization result.
View Splice Results Screen
The Bad Splice Detection feature is accessed from the Troubleshooting screen via the craft access terminal of the
H4TU-C or H4TU-R. Selecting the View Splice Results option from the Troubleshooting screen menu displays the
screen illustrated in Figure 2. Results will be reported in the Splice Detection Results column for each transceiver:
• NTF - Reported if the unit is active and no problems have been detected or the number of anomalies detected
have not yet reached the detection count threshold, which facilitates the reporting of the result to this screen.
(Eight is the present threshold.)
• LOS - Reported if the remote unit has not been detected.
• Number - Reported if an anomaly has been detected a number of times that exceeds the detection count threshold
of eight. The number shown in this column represents the number of feet from the transceiver (Reference Point)
2 61223445L1-5D
239 H4R Installation and Maintenance PracticeDescription
to that anomaly. This number will also reflect the highest anomaly count seen, as it is possible to have more than
one bad splice per circuit. This screen will report the worst (most frequently detected) anomaly.
In this example, a detection has occurred approximately 650 feet from an H4TU-C module on Loop 2 of the
HDSL4 circuit.
Circuit ID:HTSVALHDSL4 06/17/04 07:32:04
Press ESC to return to previous menu
* Note: Chronic Circuit Results are only valid after all other circuit *
* qualification tests have been performed and failed to show a trouble !! *
Splice Detector Version 1 Result Definitions:
--------------------------------------------NTF - No Trouble Found yet.
LOS - Unit not in sync.
Number - Distance from Reference point (in ft.) of suspect splice.
Reference Splice Detection Results Version Result Shown
Point Loop 1 Loop 2 Number for date
Fast Retrain is an ADTRAN proprietary feature whose intent is to minimize downtime when an intermittent non
power-related impairment (bad splice, noise burst, etc.) affects the HDSL loop and cannot be bridged.
HDSL2 and HDSL4 transceivers normally train in approximately 25 to 30 seconds. For an initial circuit turn-up,
this is not a big issue. However, once service has been established on the circuit, any large down-time will interrupt
communications on the circuit. A loss of synchronization on the HDSL loop can cause excessive down times due
not only to the 30-second HDSL retrain time, but also further delays due to the higher level protocols in the
network going through re-synchronization. On the older generation HDSL2 and HDSL4 units, a 1-second loss of
HDSL frame synchronization would cause the data pumps to retrain. This retrain would take approximately 25
seconds during which AIS would be sent to the terminating equipment. The reception of AIS by the terminating
equipment then might trigger higher level protocol re-synchronizations.
In an effort to minimize this down time, the Fast Retrain feature has been implemented. If an impairment (bad
splice, for example) causes the HDSL data pump to lose frame synchronization for 500 msec or longer, instead of
retraining, a fast retrain will be attempted. This abbreviated train can achieve data mode in 5 to 7 seconds. A
successful fast retrain should be evident by watching the Span Status screen and by reduced unavailable seconds
(UAS) in the PM data for each LOS alarm recorded.
NOTE
Fast-Retrain capable units must be installed on both ends of the HDSL4 circuit for
this feature to function properly. Also, if there is a failure of a fast retrain attempt,
for any reason, then the traditional (25-30 second) retrain will be initiated.
61223445L1-5D 3
Description239 H4R Installation and Maintenance Practice
Compatibility
The 239 H4R is used in conjunction with any T1.418 compliant span powering H4TU-C and H4TU-R. Compatible
ADTRAN HDSL4 transceiver units are listed in Tab l e 1.
Table 1. ADTRAN Unit Compatibility
Part NumberUnit Name
118141xLyTotal Access 3000 H4TU-C
122x401Ly220 H4TU-C
122x403LyDDM+ H4TU-C
122x404Ly3192 H4TU-C
122x407LySoneplex H4TU-C
122x424LyT200 H4TU-R, Local Power
122x426LyT200 H4TU-R, Span Power
x = any generic number; y = any list number
Due to span power limits, the number of H4Rs permitted in the circuit depends upon the type of H4TU-C utilized.
An ADTRAN 239 H4R provides DS1 transport on all revised resistance design (RRD) 26 AWG and/or 24 AWG
loops. Three ADTRAN 239 H4R repeaters may be added to extend the range of a loop.
Repeater placement is determined by the following criteria:
• On single H4R loops, only on the attenuation properties of the loop segment must be considered.
• For a circuit requiring two H4Rs, both segment attenuation as well as segment DC resistance requirements be
satisfied.
• For a circuit requiring three H4Rs, H4TU-C and H4TU-R hardware requirements, segment attenuation, and
segment DC resistance requirements must all be satisfied.
Refer to the “HDSL4 Deployment Guidelines” on page 6 of this practice and the Installation and Maintenance
Practice for the deployed H4TU-C.
Compliance
Tab l e 2 shows the compliance codes for the 239 H4R. The 239 H4R is NRTL listed to the applicable UL standards.
The 239 H4R is to be installed in a restricted access location and in a Type “B” or “E” enclosure only.
Table 2. Compliance Codes
CodeInputOutput
Power Code (PC)CC
Telecommunication Code (TC)X
Installation Code (IC)A–
4 61223445L1-5D
239 H4R Installation and Maintenance PracticeInstallation
This device complies with Part 15 of the FCC rules. Operation is subject to the following two conditions:
1. This device may not cause harmful interference.
2. This device must accept any interference received, including interference that may cause undesired operation.
Changes or modifications not expressly approved by ADTRAN could void the user’s authority to operate this
equipment.
3.INSTALLATION
C A U T I O N !
SUBJECT TO ELECTROSTATIC DAMAGE
OR DECREASE IN RELIABILITY.
HANDLING PRECAUTIONS REQUIRED.
After unpacking the 239 H4R, inspect it for damage. If damage has occurred, file a claim with the carrier, then
contact ADTRAN Customer Service. Refer to “Appendix A, Warranty” for further information. If possible, keep
the original shipping container for returning the 239 H4R for repair or for verification of shipping damage.
Shipping Contents
The contents include the following items:
• 239 T1 HDSL4 Repeater (H4R)
• 239 T1 HDSL4 Repeater (H4R) Job Aid
CAUTION
Electronic modules can be damaged by ESD. When handling modules, wear an
antistatic discharge wrist strap to prevent damage to electronic components. Place
modules in antistatic packing material when transporting or storing. When working
on modules, always place them on an approved antistatic mat that is electrically
grounded.
There are no manual option settings for the H4R.
H4R power is derived from an H4TU-C, independent of line impedance or wire gauge. The operating power from
the H4TU-C may also be used to span power the H4TU-R.
The 239 H4R is designed for deployment in any environmentally controlled 239-type apparatus case.
A retainer latch is available for securing the 239 H4R in the apparatus case.
When installing the ADTRAN 239 H4R refer to the Installation and Maintenance Practice for the housing being
used.
61223445L1-5D 5
Connections239 H4R Installation and Maintenance Practice
4.CONNECTIONS
All connections are made through card edge connectors.
Tab l e 3 provides the card edge pin assignments.
CAUTION
The H4R dissipates a maximum of 5.4 watts.
NOTE
Ensure that the chassis ground is securely connected to the apparatus case. Ground
pin designations are defined in Table 3 .
Table 3. H4R Card Edge Pin Assignments
PinDesignationDescription
1GNDGround
2NCNo Connect
3T1Customer Loop 1 Tip
4R1Customer Loop 1 Ring
5T1Network Loop 1 Tip
6R1Network Loop 1 Ring
7NCNo Connect
8TNetwork Loop 2 Tip
9RNetwork Loop 2 Ring
10GNDGround
11TCustomer Loop 2 Tip
12RCustomer Loop 2 Ring
5.HDSL4 DEPLOYMENT GUIDELINES
Refer to the H4TU-C Installation and Maintenance Practice, HDSL4 Deployment Guidelines section, for loop
parameters including attenuation and loop resistance considerations.
NOTE
The H4TU-C with part numbers 1221401L6, 1221403L6, and 1221404L6 support
only one H4R in the HDSL4 circuit.
Refer to the Detailed Status Screen by accessing the menus on the H4TU-C craft terminal interface for current
Signal-to-Noise Ratio Margin and Attenuation status indications for the circuit.
The ADTRAN 239 H4R is designed for installation in a prewired apparatus case, and the capacity guidelines for deployment are defined in Table 3 and
Table 4. These housing capacity numbers are based upon testing results.
Table 4. 239 H4R Capacity Guidelines for ADTRAN Housings
Circa TelecomHDSL-12A760005121212AllAllStainless Steel
Circa TelecomHDSL-12B760006121212AllAllStainless Steel
H4R Capacity Guidelines239 T1 HDSL4 Repeater (H4R) Installation and Maintenance Practice
Arris/Lucent/
AT & T
Arris/Lucent/
AT & T
Keptel® Inter
™
809
Link
Keptel® Inter
™
818/819
Link
RF809A3-XXX or
RF809B3-XXX
RF819A1 or RF819A2
RF819B1 or RF819B2
128N/A1, 3, 4, 6
7, 9, 10, 12
251216*Chamber 1:
1, 4, 7, 8, 11, 14
Chamber 2:
15, 17, 19, 20, 23,
25
ArrisKeptel Inter
Link 819 Fam
-
AT819B1U or
AT819A1U
12882, 3, 5, 6, 8, 9,
11, 12
ily
Arris/Lucent/
AT & T
Keptel Inter
Link 820 Fam
RF820AX or
-
RF820BX
2 to 8FullFullAllAllPolymer
ily
* For 16 slot use, the ambient air temperature measured 1 foot away and parallel to the housing should not exceed 115°F (46.1°C).
N/APolymer
Chamber 1:
1, 3, 5, 7, 8, 10,
12, 14
Chamber 2:
15, 16, 18, 19, 20,
22, 24, 25
2, 3, 5, 6, 8, 9,
11, 12
Polymer
Polymer
239 H4R Installation and Maintenance PracticeFront Panel LEDs
7.FRONT PANEL LEDS
The ADTRAN 239 H4R provides front panel LEDs to display status information. See Tab le 6 for a listing of the
front panel LEDs and their indications.
Table 6. Front Panel LEDs
UnitLabelIndicationDescription
239 H4R
1223445L1
LP1
NET
LP2
LP1
CUST
LP2
LL RL
/
(Y) (G)
LP1/LP2
NET
LP1/LP2
CUST
! Off
" Solid Green
4 Fast Flashing Green
4 Slow Flashing Green
" Solid Yellow
4 Flashing Yellow
" Solid Red
4 Flashing Red
! Off
" Solid Green
4 Fast Flashing Green
4 Slow Flashing Green
" Solid Yellow
4 Flashing Yellow
" Solid Red
4 Flashing Red
No span power is present
Synchronized with an Signal to Noise Ratio (SNR) margin greater than
the recommended SNR Margin Alarm Threshold
(Flashing 3 times per second) Attempting to synchronize with the
H4TU-C
(Flashing once per second) Synchronized with a SNR margin greater
than the recommended SNR Margin Alarm Threshold, and the attenua
tion is greater than the user recommended Loop Attenuation Alarm
Threshold
Synchronized with a SNR margin greater than 0 dB but less than the
recommended SNR Margin Alarm Threshold
Synchronized with a SNR margin greater than 0 dB but less than the
recommended SNR Margin Alarm Threshold, and the attenuation is
greater than the user recommended Loop Attenuation Alarm Threshold
Synchronized with a SNR margin of 0 dB
(Flashing once per second) Synchronized with a SNR margin of 0 dB,
and the attenuation is greater than the recommended Loop Attenuation
Alarm Threshold
No span power is present
Synchronized with an Signal to Noise Ratio (SNR) margin greater than
the recommended SNR Margin Alarm Threshold
(Flashing 3 times per second) Attempting to synchronize with the
H4TU-R
(Flashing once per second) Synchronized with a SNR margin greater
than the recommended SNR Margin Alarm Threshold, and the attenua
tion is greater than the user recommended Loop Attenuation Alarm
Threshold
Synchronized with a SNR margin greater than 0 dB but less than the
recommended SNR Margin Alarm Threshold
Synchronized with a SNR margin greater than 0 dB but less than the
recommended SNR Margin Alarm Threshold, and the attenuation is
greater than the user recommended Loop Attenuation Alarm Threshold
Synchronized with a SNR margin of 0 dB
(Flashing once per second) Synchronized with a SNR margin of 0 dB,
and the attenuation is greater than the recommended Loop Attenuation
Alarm Threshold
-
-
LL/RL
61223445L1-5D 9
" Solid Yellow
4 Flashing Yellow
" Solid Green
Indicates that a loopback is active at the H4R towards the H4TU-C
H4R is armed but not in loopback
Indicates that a loopback is active at the H4R towards the H4TU-R
Maintenance239 H4R Installation and Maintenance Practice
8.MAINTENANCE
The HDSL4 239 T1 HDSL4 Repeater (H4R) requires no routine maintenance for normal operation. In case of
equipment malfunction, perform an in-band loopback from the Central Office. If a malfunction is confirmed,
replace the unit.
The ADTRAN 239 H4R has looping capability through the channel allowing digital loopback in fault isolation.
The loopback is activated remotely. The type of loopbacks the H4R supports will be dependent upon the loopback
capabilities of the transceiver units utilized on the circuit. Refer to the Installation and Maintenance Practice of the
specific H4TU-C or H4TU-R for a list of loopback codes.
Performance monitoring, diagnostics, and loopbacks are also available from the craft interface at the
H4TU-C or H4TU-R.
CAUTION
When testing indicates a faulty H4R, refer to the housing Installation and Maintenance Practice for the entry and pressurization control, the replace the faulty unit.
ADTRAN does not recommend that repairs be attempted in the field. Repair services may be obtained by returning
the defective unit to ADTRAN. Refer to “Appendix A, Warranty” for further information.
9.SPECIFICATIONS
Specifications for the HDSL4 239 T1 HDSL4 Repeater (H4R) are detailed in Tab l e 7 .
10 61223445L1-5D
239 H4R Installation and Maintenance PracticeSpecifications
Specifications239 H4R Installation and Maintenance Practice
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12 61223445L1-5D
Appendix A
Warranty
WARRANTY AND CUSTOMER SERVICE
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
Refer to the following subsections for sales, support, Customer and Product Service (CAPS) requests, or further
information.