L
OOPBACK
T
ESTING
Initiate loopback testing from the maintenance menus, the front-panel MODE and SEL
pushbuttons, or a test set. Inband codes used by a test set are shown in the table below.
Table 1.
Front-Panel Alarm Messages
(a)
(a) Front-panel alarm messages are listed in order of priority.
ALRM
displays prior to any alarm message.
Pressing the LBK pushbutton initiates an Alarm Cutoff (ACO) message.
Message
Description
PWR FEED SHRT
(b)
(b) Message displays repeatedly as long as the alarm condition exists, and is not included in the priority order.
A short between the Tip and Ring of the HDSL2 pair.
PWR FEED GND
(b)
The HDSL2 loop is grounded.
PWR FEED OPEN
(b)
A line-power open condition.
LOSW
The HDSL2 loop has lost synchronization.
LLOS
No signal is detected at the DSX-1 input to the H2TU-C.
RLOS
No signal is detected at the DS1 input to the H2TU-R.
LAIS
Line Alarm Indication Signal.
RAIS
Remote Alarm Indication Signal.
LRAI
An RAI alarm (yellow) from the CPE without errors from the line unit or network.
RRAI
An RAI alarm (yellow) from the CPE with errors from the line unit or network.
xxx-LOF
The DS1 input does not contain the ESF or SF frame pattern setting of the FRMG option.
(xxx denotes either TUC or TUR.)
xxx-DBER
A system DS1 Bit Error Rate (BER) alarm. (xxx denotes either Transmission Unit
Central Office [TUC] or Transmission Unit Remote End [TUR].)
PRMF
H2TU-R Performance Report Messaging BER threshold exceeded at far end.
PRMN
H2TU-R Performance Report Messaging BER threshold exceeded at near end.
xxx-HBER
A system HDSL2 Block Error Rate (BER) alarm. (xxx denotes either TUC or TUR.)
xxx-MAL
The margin on the HDSL2 loop has dropped below the threshold setting.
(xxx denotes either TUC or TUR.)
xxx-LA
The attenuation on the HDSL2 loop has exceeded the maximum threshold value.
(xxx denotes either TUC or TUR.)
Table 2.
Front-Panel Configuration Options Using MODE and SEL
(a)
(a) Front-panel configuration options display in the order listed.
Display Code Description (default values in bold)
EQL
Sets the DSX-1 Equalizer to: EXT (external), 0 (0 to 132 ft.), 133 (133 to 265 ft.), 266 (266 to 398
ft.), 399 (399 to 532 ft.), or 533 (533 to 655 ft.).
RLBO
Sets the H2TU-R line buildout to 0 dB, -7.5 dB, or -15 dB.
LPBK
Enables (ENA) or disables (DIS) SmartJack loopback commands.
SPLB xxxx
Configures system for generic (GNLB) or special in-band loopback commands (A1LB, A2LB, A3LB, A4LB,
or A5LB).
PWRF
OFF = disables HDSL2 powering; ON = HDSL2 line voltage is -180 Vdc maximum.
HBER
1E-6 or 1E-7 = alarm activates when the HDSL2 BER alarm threshold exceeds 10
-6
or 10
-7
.
NONE = prevents generation of a system alarm due to BER.
DBER
Enables (ENA) or disables (DIS) fixed 24-hour DS1 BER alarm threshold.
DS1
DSX-1 line code = AUTO, B8ZS, or AMI.
LBTO
Loopback timeout = NONE, 20, 60, or 120 minutes or 8 or 24 hours.
FRMG
DS1 frame formatting = AUTO (Auto framing mode), SF (SuperFrame), ESF (Extended
SuperFrame), or UNFR (Unframed mode).
RDA
Enables (ENA) or disables (DIS) alarm indications due to remote DS1 LOS at H2TU-R input.
ALMP
Enables system to output an alarm pattern: AIS or LOS.
BPVT
Enables (ENA) or disables (DIS) Bipolar Violation Transparency.
NLBP
Enables the H2TU-R to transmit either AIS or LOS towards CI for any network loopback.
TLOS
Enables (ENA) or disables (DIS) a logic loopback at the H2TU-R when an LOS occurs at its DS1 input.
RTPV
Enables (ENA) or disables (DIS) remote provisioning.
PBON
Configures the power output levels of the H2TU-C network unit toward the customer to comply with
Default (DEF) or Enhanced (ENH) templates.
PBOC
Configures the power output levels of the H2TU-C customer unit toward the network to comply with
Default (DEF) or Enhanced (ENH) templates.
Table 3.
Front-Panel Diagnostic Messages
Message
(a)
(a) Normal operating messages are in bold.
Description
A=xx
The highest loop attenuation (loss of signal power) measured in dB.
ACQ
The multiplexers of the H2TU-C and H2TU-R are trying to establish synchronization.
ARM
The H2TU-C is armed to respond to Intelligent Repeater Loop (ILR) codes.
BAD RT?
The H2TU-C is not receiving a response from the H2TU-R.
FERR
A framing bit error has occurred at H2TU-C DSX-1 input.
HES
H2TU-C HDSL2 loop cyclical redundancy check (CRC) error.
LBPV
A local bipolar violation has been received at the DSX-1 input to the H2TU-C.
M=xx
The power of the received HDSL2 signal relative to noise (S/N with respect to 21.5 dB).
PWR FEED OFF
HDSL2 span power is turned off.
PWR FEED ON
HDSL2 loop is not grounded or shorted.
SIG
The transceivers of the H2TU-C and H2TU-R are trying to establish contact with each other
over the HDSL2 loop.
Table 4.
Front-Panel System Information Messages (Scroll Mode)
(a)
(a) To scroll through system information messages, press the MODE pushbutton for 3 or more seconds.
Code
Description
Code
Description
CODE xxxx
Line code (AMI, B8ZS).
LIST xx
Product list number.
FRM xxxx
Frame pattern received from the
DSX-1 (SF, ESF, or UNFR).
MARG xx
Margin threshold (0 to 15 dB). Default
is 4.
LATT xx
Loop attenuation (0 to 40 dB). Default
is 35.
VER x.xx
Firmware version.
Table 5.
Loopback Commands
Loopback
Inband Code
Description
NLOC
1111000
DSX-1 signal is looped back to the network at the H2TU-C.
NREM
1110000
DSX-1 signal is looped back to the network at the H2TU-R.
COLB
(a)
(a) Dual loopbacks can be initiated only from the front-panel MODE and SEL pushbuttons.
DSX-1 signal is looped back to the network at the H2TU-C and signal from the
customer is looped back to the customer at the H2TU-C.
RULB
(a)
DSX-1 signal is looped back to the network at the H2TU-R and signal from the
customer is looped back to the customer at the H2TU-R.
CREM
1111110
DS1 signal from customer is looped back to the customer at the H2TU-C.
CLOC
1111100
DS1 signal from customer is looped back to the customer at the H2TU-R.
SMJK
11000
DSX-1 signal is looped back to the network at the H2TU-R SmartJack module.
Loopdown
11100
Deactivates any of the above loopbacks.
Copies of this publication or the user manual (LTPH-UM-1181-01)
can be downloaded from the ADC website at www.adc.com. To
order a hard copy, please contact your sales representative.
To comply with the intrabuilding wiring requirements of GR-1089
CORE, Section 4.5.9, the shields of the ABAM-type cables that
connect the line unit DSX-1 output ports to the cross-connect
panel must be grounded at both ends.
Network
H2TU-C
H2TU-R
TLOS*
NLOC
CREM
CLOC
NREM
SMJK
* When enabled, TLOS is an automatic loopback
that occurs with an LOS at the remote DS1 input.
Toward Customer
Toward Network
Customer
Premises
DS1
DSX-1
H0025-B
HDSL2
Four-character display
Displays status, provisioning, and
alarm messages. See tables below
for a list of message descriptions.
List number
Status LED
Reports the following conditions:
DSX-1 test access jacks
Connect standard test equipment.
Craft port
To access system maintenance, provisioning, and
performance screens, connect a standard 9-pin terminal
cable between the PC serial port and the H2TU-C
craft port.
System option buttons (for manually
setting system parameters)
Use MODE and SEL to manually modify user options,
initiate loopbacks, and display DSX-1 line parameters.
1
2
3
4
Press the MODE pushbutton for 1 second and release.
The front panel alternately displays the first system
parameter and its current setting.
Press SEL to step through all possible settings for
the displayed parameter.
Press MODE to update the parameter and advance
to the next parameter.
After scrolling through all the parameters, press SEL
to confirm changes when prompted with a CONF NO
message, or press MODE to cancel all changes.
BRG
LINE
Provides non-intrusive bridging jack access
to (IN) and from (OUT) the HDSL2 span at
the DSX-1 interface. Allows monitoring of
the DS1 payloads.
Provides splitting jack access to (IN) and
from (OUT) the HDSL2 span at the DSX-1
interface.
Maintenance Terminal Modem Settings
9600 baud
8 data bits
No parity
1 stop bit
Hardware flow control: OFF
Terminal emulation: VT-100
H
2
T
U
•
C
2
3
1
MODE
SEL
OUT
BRG
IN
L
LINE
LINE
BRG
R
S
2
3
2
SETUP
STATUS
HiGain
HDSL2
H0306-A
Card-Edge Connector
14
15
16
17
18
19
20
21
22
23
24
25
Tip
DSX-1
IN
DSX-1
OUT
Ground
Factory use only
Ring
Ground
Tip 1
Ring 1
39
40
41
42
43
44
45
46
47
48
49
50
-48Vdc
1
2
3
4
5
6
7
8
9
10
11
Tip
Ring
KEY
KEY
26
27
28
29
30
31
32
33
34
35
36
37
38
12
13
Factory use only
HDSL2 Span
DCE
Retaining latch
Secures the H2TU-C.
CLEI and ECI barcode label
A Customer Remote (CREM)
or Network Local (NLOC)
loopback is in effect.
Green LED
Normal operation.
Flashing Red LED
Yellow LED
Flashing Yellow LED
System is in Armed (ARM)
mode.
HDSL2 acquisition or
system alarm.
Off
Line power is off.
Red LED
Fuse alarm.
Fuse alarm*
Factory use only
* Fuse alarm is normally floating
and at -48 Vdc when activated.
