Tektronix NetTek YBT1E1, User Manual

Page: 89 / 122

Testing a Circuit
NetTek YBT1E1 T1 & E1 Circuit Tester User Manual
3- 21
Setting up Loopback Codes
1. Tap Terminate in the Configure area.
2. Tap Loop Codes to display the Loop Codes tab.
3. Select one of the following:
H
Select the CSU or NUI option button and the associated
drop-down list to specify a pre-defined loop code.
H
Select User , then tap the keypad icon to open the numeric
keypad and enter a binary code.
4. Tap OK . The current loop code type (CSU, NUI, or User) is
displayed below the Loop Up / Loop Down button. This
configuration is similar to the Terminate configuration except
that a far end loop has been established.
Tap the Loop Down button to remove the loopback mode and return
the NetTek YBT1E1 to a standard Terminate configuration.
NOTE
. The Loop Down button appears after you have selected the
Loop Up button and successfully completed a loop up of the far end.
Using the DS0 View
The DS0 view is a vertically-rolling display that shows the
ones-density data activity of each signal time slot. The DSO view
uses unique colors to represent the percentage of ones-density from
all zeros through all ones, in 10% increments. New signal informa-
tion starts at the bottom of the display and scrolls upward.
Select the Drop DS0 button on the right side of display to open the
DS0 view. Figure 3--12 on page 3--22 shows the DSO view for the
DSO PCM31 BER test pattern.