Interpreting Line Status Indicators

Error LEDs

 

The following error LEDs indicate port error events that

 

generate communication problems:

 

 

LED

Meaning

 

 

BPV

BiPolar Violation. For an AMI-coded signal, the occurrence of a

 

pulse of the same polarity as the previous pulse causes a BPV

 

error event.

 

 

PCV

Path Coding Violation.

 

In D4 and E1-nonCRC formats, a frame synchronization bit

 

error

 

In ESF and E1-CRC formats, a CRC error

 

 

CS

Controlled Slip. Results from the replication or deletion of the

 

payload bits of the DS1 frame.

 

A Controlled Slip may be performed when there is a timing

 

difference between a synchronous receiving terminal and the

 

received signal.

 

 

Loopback LEDs

The following Loopback LEDs indicate whether the port is in a loopback mode (which can be why it isn't running normally):

LED Meaning

Payload The signal returned toward the source of the loopback command consists of the payload of the received signal (with bit sequence integrity retained), and newly-generated ESF framing.

Line The signal returned to the loopback command source consists of the full signal. Bit sequence integrity is maintained, framing is not changed, and Bipolar Violations are not removed. (See Error LEDs on page 174 for information about Bipolar violations.)

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Interphase Corporation