| 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 |
|
|
Lpbk Position | Selects the possible loopback positions: |
NONE | Option not available with |
|
|
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 |
| at the LTU toward the NTU. The actual pattern used is a 2x1015 pattern as defined by reselecting this |
| option (pressing the ENTER 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 |
August 9, 2002 | 61 |