Setting the Clock Source
Access-T can derive its clock from any of eight sources:
•
An internal crystal-controlled clock (with a frequency of 1.544 Mbps).
•
A station clock connected to the Access-T rear panel.
•
The signal received via the T1 network (line).
•
The clock received via DTE port 1, 2, 3, or 4.
•
The T1 DTE auxiliary port
To select the Access-T clock source, perform the following steps:
1.
Select
SYSTEM
from the Main Menu Line.
2.
Select the
MASTER CLOCK
option
3.
Select the
SOURCE
option and then select the desired clock source
(
INTERNAL
,
LINE
,
STATION
,
PORT1
,
PORT2
,
PORT3
, or
PORT4
).
Note:
If terminal timing mode is selected for a DTE
port, that port cannot be the master clock source.
4.
Press the
Esc
key.
5.
If the station clock option is selected in step 3, the frequency must be
specified. Select the
FREQUENCY
option and press the
Enter
key. Pos-
sible frequency values will appear on screen. Enter the desired clock
frequency and press the
Esc
key.
Note:
If any clock other than
STATION
is selected, that
clock’s frequency is displayed under
FREQUENCY
.
The displayed frequency can be changed but the
change cannot be entered.
Changing the Exit Key
If an Access-T is to be managed over a network and you are using a VT100
terminal emulation, you must change the key used to perform the “exit”
function for the Terminal Interface from
Esc
to
Tab
. Larscom recommends that
you do not make this change except for communication in such a configuration.
Note
: All Access-Ts on the same chain must have the same
EXIT key configuration.
Chapter 6
ACST-0351-005
Configuration Procedures
June 1996
6-10
