ADC ETU-751C - Manual (Page 71)

700-701-100-02 Testing
UTU-701 and ETU-751 List 1 August 9, 2002 61
Table 30. Test Menu Options
Operating Option Default Setting
Network Diagram Shows the loopback position and direction when the loopback is enabled and active.
Lpbk Dir Selects one of three loopback direction modes:
OFF No loopbacks are active.
NETWORK The loopback selected in Loopback Position is directed toward the network equipment connected to
the LTU.
CUSTOMER The loopback selected in Loopback Position is directed toward the customer's equipment connected
to the NTU.
Lpbk Loop(s) Selects the loops used in the loopback test:
NONE Option not available with single-pair HDSL card.
Lpbk Position Selects the possible loopback positions:
NONE Option not available with single-pair HDSL card.
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 31. BER Section of 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. This disrupts user payload traffic and inserts a pseudo-random bit sequence (PRBS)
at the LTU toward the NTU. The actual 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 .
ENTER