LTPE-UG-1017-01 Issue 1
Testing
UTU-731 List 1 and UTU-732 List 1
February 15, 2001
65
Option
Default Setting
Lpbk Timeout
Selects one of three loopback timeouts:
NONE
Disables automatic timeout cancellation of all loopbacks.
20
Automatically cancels any loopback 20 minutes after initiation.
120
Automatically cancels any loopback 120 minutes after initiation.
Table 26.
BER Options in Test Menu
Field
Description
BER Test
Selects the state of the BER test.
STOP
Terminates the current test and resumes normal transmission of
user payload. Prior BER tests are maintained for reference on the
screen. STOP must be selected to terminate the BER test prior to
exiting the screen.
RESTART
Begins BER test. Disrupts user payload traffic and inserts a
pseudo-random bit sequence (PRBS) at the LTU toward the NTU.
The pattern used is a 2x10
15
pattern as defined by reselecting this
option (pressing the
key) while the test is running. This
entry reinitiates the BER values and restarts the test.
Det. Status
Displays the current status of the BER detector at the LTU.
NOT ACTIVE
Displays while the BER is not running.
SYNCING
Indicates that the BER qualification period is in progress (128
received bits are compared to the PRBS).
IN SYNC
Indicates that the BER test is in progress. The BER meter
accumulates errors once per test interval (16 seconds). In a high
bit error environment the test interval is shortened and the BER
meter is updated every second.
Test Time
Displays the elapsed test time for the BER test.
Bit Errors
Displays the number of bits received that did not match the PRBS
pattern. This field is updated every 30 seconds, with a maximum
value of 255 per update.
BER
Displays the Bit Error Rate computer for the current test. This
field is updated very 16 seconds, as is displayed in exponential
form. The lowest positive displayable value is 1x10
-11
.
Table 25.
Loopback Options in Test Menu (Cont.)
ENTER
