CANOGA PERKINS 2461 E1 Modem - Manual (Page 48)

EdgeAccess Universal Chassis System
• Remote BI
Remote electrical interface looped back. Remote signals looped back
on the fiber side as well. In a Bi-Directional Loopback (Local BI and
Remote BI), data is looped back in both directions, assuring a stricter
standard of error checking.
• Local Both
Both local and remote modems have their electrical interface looped
back.
• Clear All
This clears all the loopbacks on the local and remote units. This
function must be used before a new loopback is selected.
2. Loopback Control Mode: Use the Space Bar to toggle through Software and Hardware
options
• Software
Software loopback tests are more comprehensive than hardware
tests. Hardware loopback tests are not available on the rack mount
modem. When this mode is selected, the Loopback switch on a
stand alone modem has no affect on the loopback mode.
• Hardware
Hardware options are only available on the stand alone modem, and
are set with a switch on the modem front panel. Software loopback
options will override hardware options. On the stand alone modem,
Loopback is enabled or disabled via the loopback switch on the front
panel. Once in Software Mode, you must enable or disable
Loopbacks from the Loopback screen via the VT100 terminal or
SNMP screen.
Note: All modems in the link should be set to the same Loopback Control Mode.
3. Electrical Line Relay: Toggles through Open and Closed. This function is used to allow
testing the link that failed in a redundant configuration. If problems
occur in a redundant modem link, you can determine which modem
or cable is failing by doing the following:
¾ Disconnect the Y cables at local and remote ends
¾ Set the Electric Line Relay to Closed
¾ Perform an End to End Bit Error Rate Test
4. BERT Reset: Press Enter to reset the timer.
Note: Prior to changing a loopback selection, Clear All must be performed.
Figures 32 through 37 are loopback configuration diagrams for the 2461 modem.
2461 Modem User Manual 5-4