Interphase Tech iSPAN 5535 PRI - Manual (Page 132)

Interpreting LineStatus Indicators
112 Interphase Corporation
Error LEDs
The following error LEDs indicate port error events that
generate communication problems:
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
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.
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 112 for information about Bipolar violations.)