Patton electronic 2720 Test Pattern Idle default Options Idle or Sending, Selected Pattern

RxPr The Model 2720 is receiving a preparatory pattern.

Sack The Model 2720, upon receiving a preparatory pattern, sends an acknowledgement message.

RL The Model 2720 is in remote loopback mode.

RxTr The Model 2720 is receiving a terminate loopback mes- sage.

Wt1s The Model 2720 is waiting for a sequence of all ones and will time out if it does not receive it.

IdleP The Model 2720 is sending a QRSS, 511 or 2047 pattern.

Off The Model 2720 is in local loopback.

cTest Pattern Idle (default) Options: Idle or Sending

To send a pattern, press the ‘c’ key and press <spacebar> to send the test pattern. The “OK” message indicates the received test pattern is error-free. The “BE” message indicates errors in the received pat- tern.

Idle Indicates that Model 2720 is not sending a pattern.

Sending Indicates that 2720 is sending a pattern.

dError Insertion Off (default) Options: On, Off

You may inject intentional errors into the test pattern by turning Error Insertion ON. The Error (ERR) LED will blink once per second.

eSelected Pattern

Options: QRSS, 511, or 2047

Use this option to select the test pattern used to test the link.

NI STATUS

The Network interface (NI) status is shown in the middle of the Diagnostics/Statistics screen. The brackets are empty when the link is operating normally. In this example, various two or three-letter messages are displayed within the brackets, illustrating what you may see if the Model 2720 is not connected at all or is in a loss of signal condition. Here are the eight status messages.

Excessive zeros [EXZ], i.e., lack of pulses, detected. This condition may occur if the unit is not connected to the network, in which case the EXZ is displayed continuously. If EXZ comes on intermittently, there may be a frame, line code or data rate mismatch between the near and far-end units.

Receiver Carrier Loss [RCL] occurs when 192 consecutive zeros have been detected at the network interface. RCL clears when a pulse is detected.

Frame Bit Error [FE] occurs when there is an error in the framing bit sequence. This may happen due to a disconnected line, mismatched framing formats or severe errors in the data stream. This error may indicate a noisy line or cable condition. This error may indicate a noisy line or cable connection if the frames appear to be set correctly.

Severe Frame Error [SE] occurs when the framing error exceeds a certain threshold of errors. This may happen due to a disconnected line, an extremely noisy connection, or mismatched framing.

Loss of Sync [LOS] occurs when the T1 framer in the unit cannot synchronize itself to the received data stream. This may happen due to a disconnected line.

Out of Frame [OOF] occurs when no valid frame structure can be found. This may happen due to a disconnected line or mismatched framing or mismatched framing.

Alarm Indication Signal [AIS] indicates that the remote unit or the central office is sending a Blue Alarm, because it is not receiving a sig- nal; the alarm is an unframed all-ones signal, mainly used to keep the line alive and to indicate that it is not receiving any signal. This may indicate that the local unit is receiving a good signal, but that the trans- mit link may be broken.

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