B&B Electronics 850-14400--15 - Manual - Manual (Page 9)

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Loopback (DIP Switch S1, Position 1)
This switch enables or disables the loopback feature. When this feature is enabled,
the data line (Coax or Fiber) set by the “Loopback Type” DIP Switch is looped back.
By default this feature is DISABLED.
This feature can be controlled by SNMP management software (iView 2 ) when the
iMcV-DS3/E3/STS-LineTerm module, configured as a HOST, is installed in a managed
chassis.
Loopback Type (DIP Switch S1, Position 2)
This switch identifies which data line is looped back when the Loopback DIP Switch
is enabled. The data line loopback selection can specify either a Fiber Loopback or a
Coax Loopback.
By default this feature is COAX.
This feature can be controlled by SNMP management software (iView 2 ) when the
HOST iMcV-DS3/E3/STS-LineTerm module is installed in a managed chassis.
Fault Loopback (DIP Switch S1, Position 4)
This switch enables or disables the Fault Loopback feature. A normal fault Loss Of
Signal (LOS) will cause an Alarm Indication Signal (AIS) to be sent on to the next line
segment. This feature provides for a fault condition to be sent back towards the
direction of the detected fault. In this way, both upstream and downstream craft
personnel are alerted to a single fault.
The Fault Loopback feature uses the iMcV-DS3/E3/STS-LineTerm module LEDs to
indicate that a loss of one strand of fiber has occurred. When a strand becomes
unavailable, the module at the receiver-end detects the LOS of the fiber link and
lights the LOS LED. The module then responds by sending a Remote Alarm
Indication (RAI) signal back to the Fiber line turning ON the RAI LED at the far end of
the line and sending AIS to the COAX Port. The RAI LED is now ON at the source of
the Fiber fault. By using the Fault Loopback Function, a local site administrator can
quickly determine where a fiber fault is located from either end of the fiber line.
The AIS is transmitted as an M13 framed all-ones signal for DS3. For E3/STS and STS,
the AIS signal is an unframed all-ones pattern.
By default this feature is ENABLED.
This feature can be controlled by SNMP management software (iView 2 ) when the
HOST iMcV-DS3/E3/STS-LineTerm module is installed in a managed chassis.