User`s guide

Section 360−381−C02

4.11 Loopback Test (ISDN − Primary T1 Only)

Use the Loopback test to check where on the line problems are occurring when an alarm is reported on the card.

This test applies only when the channel mode is set to LUNT. See the ISDN documentation for additional loop-

back information.

Use the following steps to enable/disable the card loopback.

Step Action System Response

1. Select which card you want to test (Card 1, Card 2

or half size)

Displays your choice

2. Select the channel number you want to test. Use

the <Tab> key to highlight the channel number and

<Enter> to select the channel

Flags the channel

3. Select the test pattern (NO or YES) Displays your choice (for future use)

4. Select the loopback type (local, LULT or NT1) or

select to release loopback

Displays your choice

5. Select Apply New Settings to enable/disable the

loopback

If you have chosen to enable the loopback, this will

start the test. You will have to go back into this

menu and select Disable to end the test. Verify

that loopback is enabled by looking at the front

panel of the card you are testing. The LB LED

should be ON.