7
Section 61246001L2-5, Issue 2
61246001L2-5B
Figure 6. HDSL Loopbacks
In addition to network-side loopbacks, the HTU-C M
provides customer-side loopbacks initiated by using
the terminal control port. In this mode, either an AIS
signal or customer data is supplied to the network.
Customer side loopbacks must be deactivated by using
the terminal.
5. CONTROL PORT OPERATION
The HTU-C M provides a faceplate-mounted DB9
connector that supplies an RS-232 interface for
connection to a controlling terminal. The pinout of the
DB9 is illustrated in Figure 7.
The terminal interface operates at data rates from 1.2
kbps to 19.2 kbps. The asynchronous data format is
fixed at 8 data bits, no parity, and 1 stop bit. The
Figure 7. RS-232 (DB9) Pin Assignments
6
7
8
9
1
2
3
4
5
TXD (Transmit Data)
RXD (Receive Data)
SGN (Signal Ground)
supported terminal type is VT 100 or compatible.
NOTE:
If you are using a personal computer (PC)
with terminal emulation capability, be sure
to disable any power saving programs.
Otherwise, communication between the PC
and the HDSL unit may be disrupted, resulting
in misplaced characters or screen timeouts.
When operating the unit in the ADTRAN
E220 Shelf with an HFAC (HDSL shelf
controller), all remote terminal operation
must be made through the control port of the
shelf controller, not the HTU-C M. Terminal
operation via the HFAC control port will
vary slightly from that described in the
practice for the HTU-C M.
Operation
For abbreviations used in the screen diagrams, see
Table 5.
The screens illustrated in Figures 8 through 18 apply
to an HDSL circuit deployed with ADTRAN’s Low
Voltage HDSL technology. The circuit includes an
HTU-C M, HTU-R, and two HREs. This scenario
was chosen for inclusiveness of functionality.
However, other configurations are possible and their
displays will vary slightly from those shown in this
section.
A terminal session is initiated by plugging into the
faceplate-mounted DB-9. An Introductory Menu will
then appear, as illustrated in Figure 8.
From the Introductory Menu, the Main Menu may be
selected. The Main Menu provides access to detailed
performance and configuration information, as
DSX-1
HTU-C
LOCAL
LOOP
HTU-C Network-Side Loopback
HTU-R
HTU-C
LOCAL
LOOP
HTU-R Customer-Side Loopback
HTU-R
HTU-C
LOCAL
LOOP
HTU-C Customer-Side Loopback
HTU-R
X
X
DS1
DSX-1
HTU-C
LOCAL
LOOP
HTU-R Network-Side Loopback and/or
HTU-R NIU Loopback
HTU-R
X
DS1
DS1
DS1
X
AIS
AIS
HTU-C
HRE Network-Side Loopback
HTU-R
DS1
DSX-1
HRE
AIS
AIS
AIS
X
X = Signal Inactive
D = Data Sent
X
HTU-C
Dual HRE Network-Side Loopback
HRE #2
DSX-1
HRE #1
HTU-R
DS1
AIS
X
X
