EXFO FTB-8500 Series for FTB-500 - Manual (Page 421)

Tools Tabs
Ethernet and Fibre Channel Application 407
ADC Configuration
Loopback
Allows sending a loopback request to the selected ENIU.
Note: If the selected ENIU becomes invalid, the loopback request cannot be sent.

Request: Allows the selection of the loopback request. Choices are
Enabled and Disabled.

Send: Sends an Enable or Disable Loopback request as selected in the
Request field.

Loopback Status: Indicates the loopback status of the selected ENIU.
Enabled when the Ethernet and Fibre Channel Application has
received the confirmation that the ENIU is in loopback mode.
Disabled when the Ethernet and Fibre Channel Application has not
received the confirmation that the ENIU is in loopback mode or when
the ENIU is not in loopback mode.
In progress when a loopback request has been sent to the ENIU but
the Ethernet and Fibre Channel Application has not received the
confirmation yet.
“--” when no valid ENIU is selected.

Timeout: Allows selection of the timeout when it is enabled. Choices
are from 1 to 10080 minutes. The default setting is 60 minutes.
Enable: Allows the activation of the timeout. When enabled the
timeout value can be set. When disabled, the timeout is infinite.